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Underground Space 2023年第6期13卷 228-240页

作者： Weixin Sun Hanlong liu Wengang Zhang Songlin liu Liang Han School of Civil Engineering Chongqing UniversityChongqing 400045China Key Laboratory of New Technology for Construction of Cities in Mountain Area Chongqing UniversityChongqing 400045China National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas Chongqing UniversityChongqing 400045China

Groundwater plays an essential role in stabilizing underground ***,hydrostatic uplift forces from groundwater can create safety *** paper obtained the groundwater buoyancy reduction coefficients of 36 types of clays through model tests and conducted a finite element simulation to obtain the buoyancy reduction coefficients of additional clays with varying soil *** learning methods,including extreme gradient boosting(XGBoost)and random forest(RF)algorithms,were used to analyze and identify the soil parameters that have a significant impact on the reduction of groundwater *** was found that the permeability coefficient and saturation are the primary factors that influence the reduction of groundwater ***,the prediction models developed by XGBoost and RF were compared,and their accuracy was *** research findings can serve as a reference for designing underground structures that can withstand the potential risk of buoyancy in clay.

关键词： Clay Buoyancy reduction coefficient Numerical simulation Model test Machine learning

CFD–DEM–CVD multi-physical field coupling model for simulating particle coating process in spout bed

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Particuology 2019年第1期17卷 67-78页

作者： Malin liu Meng Chen Tianjin Li Yaping Tang Rongzheng liu Youlin Shao Bing liu Jiaxing Chang Institute of Nuclear and New Energy Technology Collaborative Innovation Center of Advanced Nuclear Energy TechnologyTsinghua UniversityBeijing 100084China

Particle coating is a very important step in many industrial production processes as the particle coating layers may fix surfaces with unique advantages. Given the limitation and disadvantages of the existing simulation methods, a coupled CFD–DEM–CVD multi-physical field model for particle-coating simulations has been established taking into account the velocity field, temperature field, concentration field, and deposition model. In this model, gas behavior and chemical reactions are simulated in the CFD frame based on the conservation laws of mass, momentum, and energy. The particle behavior is simulated in the DEM frame based on the gas–solid interphase force model and contact force model. The deposition behavior is simulated in the CVD frame based on the particle movement–adhesion–deposition model. The coupled model can be implemented in Fluent-EDEM software with their user definition function and application programming interface. The particle coating process involving the pyrolysis of acetylene was investigated, and the effect of bed temperature and inlet gas velocity on deposition rate and coating efficiency were investigated based on the proposed model with adjustable deposition coefficients. Both the average deposition layer mass and the average deposition layer thickness were found to be proportional to the elapsed time and increased at the rate of about 1.05 × 10^-2 mg/s and 3.45 × 10^-4 mm/s, respectively, setting the inlet gas velocity to 11 m/s and bed temperature to 1680 K. A higher temperature and larger inlet gas velocity lead to a larger deposition rate, but the coating efficiency decreases because of limits imposed by the chemical reaction. At a bed temperature of 1280 K, the average deposition rate is 7.40 × 10?3 mg/s when the inlet gas velocity is set to 11 m/s, which is about double the deposition rate when the inlet gas velocity is set as 5 m/s. The proposed model can provide some guidance for the operating conditions and parameters design of t

关键词： Particle coating process CFD–DEM–CVD Multi-physical field Chemical vapor deposition model Multiscale simulation

Advances in self-assembly-based circularly polarized luminescent materials

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Science China Chemistry 2024年第10期67卷 3247-3257页

作者： Bing-Hao liu Yang Zong Na liu Zong-Quan Wu State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012China The School of Pharmaceutical Sciences Jilin UniversityChangchun 130021China

Circularly polarized luminescent(CPL)materials have garnered attention for their diverse applications,including three-dimensional(3D)imaging,bio-imaging,chiral sensing,and other emerging ***,the fabrication of CPL-activated materials required the use of chiral luminescent small *** introduction of the idea of self-assembly has transformed the production of CPL-activated materials,providing new and promising opportunities for their *** utilizing self-assembly,it is now feasible to produce chiral nano-assemblies with CPL activity not only from chiral molecules but also from non-chiral substances and inorganic *** addition,self-assembly routes provide a way to increase the asymmetry factor,creating possibilities for additional refinement and adjustment of CPL material *** review offers a summary of the current progress and developments in the self-assembly of small molecules and polymers,with a specific emphasis on their capacity to create or enhance CPL in different *** aim of this review is to inspire interest in optical materials that are based on the principles of self-assembly.

关键词： circularly polarized luminescence photochemistry self-assembly chiral materials

Electrodeposition and Characterization of Ni/Ti_3Si(Al)C_2 Composite Coatings

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Journal of Materials Science & Technology 2011年第11期27卷 1016-1024页

作者： Ying Liang Mingyue liu Jixin Chen Xiaoxia liu Yanchun Zhou Department of Chemistry Northeastern University Shenyang 110819 China Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

Pure nickel and Ni/Ti3Si（AI）C2 composite coatings were prepared by electrodeposition method from an additive-free nickel Watt＇s bath and were characterized by X-ray diffraction, laser confocal microscopy and scanning electron microscopy. The effect of current and Ti3Si（AI）C2 concentration in the solution on the composition, grain size, preferred orientation and surface morphology of the electrodeposited coatings were investigated. （200）-oriented Ni coatings could be deposited at high current （62.5 mA）, while （220）-oriented Ni coatings could be obtained at low current （25 mA）. However, the presence of Ti3Si（Al）C2 particles disturbed the surface texture of Ni crystallites in the composite coatings. Based on the simulated morphology and the observed microstructure, the mechanisms for the change of preferred orientation and crystallite shapes in the presence of Ti3Si（Al）C2 particles were discussed. Moreover, microhardness and friction properties of pure nickel and Ni/Ti3Si（Al）C2 composite coatings were also compared.

关键词： Ni/TiaSi(Al)C2 composite coatings Electrodeposition Preferred orientation Microstructure Mechanical properties

LegoDroid: flexible Android app decomposition and instant installation

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Science China(Information Sciences) 2023年第4期66卷 155-173页

作者： Yi liu Yun MA Xusheng XIAO Tao XIE Xuanzhe liu School of Computer Science Peking University Key Laboratory of High Confidence Software Technologies(Peking University) Ministry of Education Institute for Artificial Intelligence Peking University Department of Computer and Data Sciences Case Western Reserve University

Current mobile applications(apps) have become increasingly complicated with increasing features that are represented on the graphical user interface associated with application programming interfaces(APIs) to access backend functionality and data. Meanwhile, apps suffer from the “software bloat” in volume. Some app features may be redundant, with respect to those features(from other apps) that the users already desirably and frequently use. However, the current app release model forces users to download and install a full-size installation package rather than optionally choosing only their desired features. Large-size apps can not only increase the local resource consumption, such as CPU, memory, and energy, but also inevitably compromise the user experience, such as the slow load time in the app. In this article, we first conduct an empirical study to characterize the app feature usage when users interact with Android apps,and surprisingly find that users access only a very small subset of app features. Based on these findings,we design a new approach named Lego Droid, which automatically decomposes an Android app for flexible loading and installation, while preserving the expected functionality with a fast and instant app load. With such a method, a slimmer bundle will be downloaded and host the target APIs inside the original app to satisfy users' requirements. We implement a system for Lego Droid and evaluate it with 1000 real-world Android apps. Compared to the original full-size apps, apps optimized by Lego Droid can substantially improve the load time by reducing the base bundle and feature bundles by 13.06% and 10.93%, respectively,along with the app-package installation size by 44.17%. In addition, we also demonstrate that Lego Droid is quite practical with evolving versions, as it can produce substantial reusable code to alleviate the developers' efforts when releasing new app versions.

关键词： performance software bloat instant installation mobile applications program analysis

超声引导下腰丛复合坐骨神经阻滞麻醉对老年股骨粗隆间骨折患者的效果及安全性分析

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中国现代药物应用 2025年第2期19卷 121-124页

作者：刘建秀济南市第三人民医院麻醉科 250132

目的探讨老年股骨粗隆间骨折临床治疗中应用超声引导下腰丛复合坐骨神经阻滞麻醉(LPSNB)的效果以及安全性。方法 98例老年股骨粗隆间骨折患者,按照抽签法分成研究组、对照组,每组49例。两组患者均实施人工股骨头置换术进行治疗,对照组... 详细信息

目的探讨老年股骨粗隆间骨折临床治疗中应用超声引导下腰丛复合坐骨神经阻滞麻醉(LPSNB)的效果以及安全性。方法 98例老年股骨粗隆间骨折患者,按照抽签法分成研究组、对照组,每组49例。两组患者均实施人工股骨头置换术进行治疗,对照组开展蛛网膜下腔阻滞与硬膜外联合麻醉,研究组患者开展超声引导下腰丛复合坐骨神经阻滞麻醉。对比两组运动、感觉神经阻滞起效和维持时间,视觉模拟评分法(VAS)评分,血流动力学指标[心率(HR)、平均动脉压(MAP)],麻醉不良反应发生情况。结果研究组运动神经阻滞起效时间和维持时间分别为(9.21±2.15)、(252.26±34.23)min,感觉神经阻滞起效时间和维持时间分别为(6.18±1.69)、(271.54±40.81)min;对照组运动神经阻滞起效时间和维持时间分别为(15.09±2.93)、(207.75±32.54)min,感觉神经阻滞起效时间和维持时间分别为(12.53±2.04)、(228.42±35.67)min;研究组运动、感觉神经阻滞起效时间比对照组更短,维持时间长于对照组(P<0.05)。研究组患者术后2、12、24 h的VAS评分分别为(3.19±0.47)、(2.36±0.32)、(1.69±0.15)分,与对照组的(4.24±0.68)、(3.81±0.42)、(2.87±0.29)分比较更低(P<0.05)。术后,研究组患者的HR(80.35±10.28)次/min、MAP(90.31±11.76)mm Hg(1 mm Hg=0.133 kPa)比对照组的(87.21±10.23)次/min、(99.98±12.27)mm Hg低(P<0.05)。研究组患者的麻醉不良反应发生率4.08%比对照组的16.33%低(P<0.05)。结论老年股骨粗隆间骨折患者治疗中实施超声引导下腰丛复合坐骨神经阻滞麻醉能够增强麻醉效果,缩短麻醉起效时间,降低对血流动力学的影响,且能够降低患者术后的疼痛感,且不会出现严重的不良反应。

关键词：超声引导下腰丛复合坐骨神经阻滞麻醉股骨粗隆间骨折老年

Highly improved resistive switching performances of the self-doped Pt/HfO_2:Cu/Cu devices by atomic layer deposition

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Science China(Physics,Mechanics & Astronomy) 2016年第12期59卷 72-77页

作者： Sen liu Wei Wang QingJiang Li XiaoLong Zhao Nan Li Hui Xu Qi liu Ming liu College of Electronic Science and Engineering National University of Defense Technology Key Laboratory of Microelectronic Devices & Integrated Technology Institute of Microelectronics Chinese Academy of Sciences Department of Physics Hubei Nuclear Solid Physics Key Laboratory and Center for Ion Beam Application Wuhan University

Metal-oxide electrochemical metallization (ECM) memory is a promising candidate for the next generation nonvolatile *** this memory suffers from large dispersion of resistive switching parameters due to the intrinsic randomness of the conductive filament. In this work, we have proposed a self-doping approach to improve the resistive switching characteristics. The fabricated Pt/HfO_2:Cu/Cu device shows outstanding nonvolatile memory properties, including high uniformity, good endurance, long retention and fast switching speed. The results demonstrate that the self-doping approach is an effective method to improve the metal-oxide ECM memory performances and the self-doped Pt/HfO_2:Cu/Cu device has high potentiality for the nonvolatile memory applications in the future.

关键词： resistive switching nonvolatile memory ECM Cu dopant

碳达峰碳中和目标下的碳排放标准化管理体系建设

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中国标准化 2025年第2期 52-54页

作者：刘海波内蒙古自治区质量和标准化研究院

在全球应对气候变化的背景下,碳达峰和碳中和目标成为各国的战略重点。本文探讨了碳排放标准化管理体系建设的重要性。通过分析当前碳排放管理现状和存在的问题,如数据不准确、标准不统一等,提出了建设统一核算报告标准、完善政策法规... 详细信息

在全球应对气候变化的背景下,碳达峰和碳中和目标成为各国的战略重点。本文探讨了碳排放标准化管理体系建设的重要性。通过分析当前碳排放管理现状和存在的问题,如数据不准确、标准不统一等,提出了建设统一核算报告标准、完善政策法规、推动技术创新等措施。这些措施不仅有助于提升企业绿色转型和环境管理水平,也能有效支持国家和地区的减排目标。建立标准化管理体系将为实现可持续发展和经济绿色增长提供坚实基础。

关键词：碳达峰碳中和标准化管理体系碳排放控制

PGSLM:Edge-Enabled Probabilistic Graph Structure Learning Model for Traffic Forecasting in Internet of Vehicles

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China Communications 2023年第4期20卷 270-286页

作者： Xiaozhu liu Jiaru Zeng Rongbo Zhu Hao liu School of Automation Wuhan University of TechnologyWuhan 430070China College of Informatics Huazhong Agricultural UniversityWuhan 430070China

With the rapid development of the 5G communications,the edge intelligence enables Internet of Vehicles(IoV)to provide traffic forecasting to alleviate traffic congestion and improve quality of experience of users *** enhance the forecasting performance,a novel edge-enabled probabilistic graph structure learning model(PGSLM)is proposed,which learns the graph structure and parameters by the edge sensing information and discrete probability distribution on the edges of the traffic road *** obtain the spatio-temporal dependencies of traffic data,the learned dynamic graphs are combined with a predefined static graph to generate the graph convolution part of the recurrent graph convolution *** the training process,a new graph training loss is introduced,which is composed of the K nearest neighbor(KNN)graph constructed by the traffic feature tensors and the graph *** experimental results show that,compared with existing models,the proposed PGSLM improves the traffic prediction performance in terms of average absolute error and root mean square error in IoV.

关键词： edge computing traffic forecasting graph convolutional network graph structure learning Internet of Vehicles

Biologic risk and source diagnose of 16 PAHs from Haihe River Basin, China

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Frontiers of Environmental Science & Engineering 2016年第1期10卷 46-52页

作者： Qiuying CHEN Jingling liu Feng liu Binbin WANG Zhiguo CAO State Key Joint Laboratory of Environmental Simulation and Pollution Control & School of Environment Beijing Normal University Beijing 100875 China College of Chemistry and Life Science Shenyang Normal University Shenyang 110034 China

Surface sediments of rivers can exhibit spatial and temporal variations in contaminant concentrations that may significantly affect risk evaluations. As to pollution control and remediation of watershed, large-scale and further background data on PAHs in China were required urgently. Spatial distribution and compositional character- istics of 16 polycyclic aromatic hydrocarbons （PAHs） in surface sediments from Haihe River Basin were investi- gated. A method based on effects range （ER） was used to assess ecosystem risk of ZPAHs （the total of 16 PAH） sensitively and accurately. The results indicated that ∑PAHs content levels ranged from 257 to 16901 μg·kg-1 dry weight. The lower tings predominated in the samples, and 2-, 3-, 4-, 5- and 6-ring PAHs accounted for 12%, 21%, 30%, 30%, and 7% respectively in total PAHs. The ratio of F1 / （F1 ＋ Py） uniformly distributed in the interval 0.20- 0.80, indicating that it may be affected by petroleum origin, oil combustion, biomass and coal combustion jointly. ∑PAHs in Cetian （S6）, Dongwushi （S19）, Handan （S20）, Aixinzhuang （S21） and Tianjin （S37） exceeded effects range low （ERL）, in which biologic effects were in a medium level with an adverse effect on biologic organisms. Thus, it is necessary to strengthen the PAHs monitoring and research of the Haihe River Basin.

关键词： polycyclic aromatic hydrocarbons (PAHs),biological effects sediment Haihe River