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三维Keller-Segel-Navier-Stokes方程弱解的整体存在性

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数学学报（中文版） 2020年第5期63卷 495-504页

作者：陆生琪陈淼超刘其林三江学院数理部南京210012 巢湖学院应用数学学院合肥238000 东南大学数学学院南京211189

本文证明具有logistic源的一个3维Keller-Segel-Navier-Stokes方程弱解的整体存在性,并研究了弱解的长时间行为.

关键词：趋化 Navier-Stokes 弱解长时间行为

两类El Nino事件对Hadley环流及中国气候的影响分析

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兰州大学学报（自然科学版） 2017年第5期53卷 636-645页

作者：李艳马百胜王琪路瑶王嘉禾兰州大学大气科学学院半干旱气候变化教育部重点实验室兰州730000

利用1979-2014年的NCEP/NCAR再分析资料,分析了两类El Ni?o事件对Hadley环流及中国地区降水和气温的影响.结果表明,无论在冷季还是暖季,El Ni?o事件使得Hadley环流增强但并未改变Hadley环流中上升支及下沉支的位置;在暖季El Ni?o Modok... 详细信息

利用1979-2014年的NCEP/NCAR再分析资料,分析了两类El Ni?o事件对Hadley环流及中国地区降水和气温的影响.结果表明,无论在冷季还是暖季,El Ni?o事件使得Hadley环流增强但并未改变Hadley环流中上升支及下沉支的位置;在暖季El Ni?o Modoki事件使得Hadley环流的上升支和下沉支均发生北移,在冷季则没有这种特征.El Ni?o对Hadley环流的影响较El Ni?o Modoki要大,是由两类El Ni?o事件下海温异常分布型的不同造成的.El Ni?o事件下中国南方易出现低温、洪涝,北方易发生高温、干旱,东北易出现冷夏,且易导致暖冬现象.当发生El Ni?o Modoki事件时,在冷季,中国地区气温分布表现为北部和东部地区偏低,西部及西南部地区较高;在暖季,中国东北地区表现为较强的增温现象,长江以南地区的降水较气候平均态偏少.选择两类El Ni?o事件对Hadley环流影响最大的个例,发现中国气温、降水的异常特征与两类El Ni?o事件影响中国气候变化的统计规律基本相符,表明两类El Ni?o事件对中国气候影响的不同,很大程度上是由于其对Hadley环流的影响不同造成的,其他环流系统的作用使得最终影响更为复杂.

关键词： El Nino事件 El Nino Modoki事件 Hadley环流中国气候

Staged dendrite suppression for high safe and stable lithium-sulfur batteries

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Journal of Energy Chemistry 2025年第1期100卷 674-683页

作者： Jun Jiang Zhenjie lu Yanwen Ding Shujun Liu Zhijie qi Tian Tang Yunfan Zhang Zhiyuan Ma Jingwen Sun Liang Xue Wenyao Zhang Pan Xiong Xin Wang Junwu Zhu Yongsheng Fu Key Laboratory for Soft Chemistry and Functional Materials of Ministry of Education Nanjing University of Science and Technology Jiangsu Pylon Battery Co.Ltd

The unavoidable dendrite growth and shuttle effect have long been stranglehold challenges limiting the safety and practicality of lithium-sulfur ***,we propose a dual-action strategy to address the lithium dendrite issue in stages by constructing a multifunctional surface-negatively-charged nanodiamond layer with high ductility and robust puncture resistance on polypropylene （PP） *** uniformly loaded compact negative layer can not only significantly enhance electron transmission efficiency and promote uniform lithium deposition,but also reduce the formation of dendrite during early deposition *** importantly,under the strong puncture stress encountered during the deterioration of lithium dendrite growth under limiting current,the high ductility and robust puncture resistance（145.88 MPa） of as-obtained nanodiamond layer can effectively prevent short circuits caused by unavoidable lithium *** Li||Li symmetrical cells assembled with nanodiamond layer modified PP demonstrated a stable cycle of over 1000 h at 2 mA cm-2with a polarization voltage of only 29.3 ***,the negative charged layer serves as a physical barrier blocking lithium polysulfide ions,effectively mitigating capacity *** improved cells achieved a capacity decay of only 0.042%per cycle after 700 cycles at 3 C,demonstrating effective suppression of dendrite growth and capacity attenuation,showing promising prospect.

关键词： Lithium-sulfur batteries Staged dendrite suppression Shuttle effect Surface-negatively-charged nanodiamond

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砌体含参数本构关系统一模型研究

四川建筑科学研究 2016年第5期42卷 10-13页

作者：黄榜彪廖天权朱基珍张贝李治盛琪刘阳卢强广西科技大学土木建筑工程学院广西柳州545006 华中科技大学光学与电子信息学院湖北武汉430074

为建立一个含参数砌体本构关系统一模型,应用能量原理和损伤力学理论解释了砌体单轴受压过程中损伤能量与热量释放的关系,定义了损伤变量。通过选取的一个损伤函数,结合砌体轴压作用下应力-应变曲线的特征,提出了砌体受压含参数本构关... 详细信息

为建立一个含参数砌体本构关系统一模型,应用能量原理和损伤力学理论解释了砌体单轴受压过程中损伤能量与热量释放的关系,定义了损伤变量。通过选取的一个损伤函数,结合砌体轴压作用下应力-应变曲线的特征,提出了砌体受压含参数本构关系模型,并依据烧结页岩多孔砖砌体轴压试验结果,验证此含参数统一本构关系的正确性,对于不同材料的块体,只需结合其砌体轴压试验的峰值应力与应变,即可得到具体的本构关系表达式。

关键词：页岩多孔砖本构关系砌体抗压强度损伤

Spatiotemporal characteristics and influencing factors of vegetation water use efficiency on the Tibetan Plateau in 2001–2020

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Journal of Geographical Sciences 2025年第1期 39-64页

作者： HE Chenyang WANG Yanjiao YAN Feng lu qi School of Ecological and Environmental Science East China Normal University Institute of Ecological Conservation and Restoration Chinese Academy of Forestry National Climate Center China Meteorological Administration

Water use efficiency （WUE）,as a pivotal indicator of the coupling degree within the carbon–water cycle of ecosystems,holds considerable importance in assessment of the carbon–water balance within terrestrial ***,in the context of global warming,WUE evolution and its primary drivers on the Tibetan Plateau remain *** study employed the ensemble empirical mode decomposition method and the random forest algorithm to decipher the nonlinear trends and drivers of WUE on the Tibetan Plateau in 2001–*** indicated an annual mean WUE of 0.8088 gC/mm·m2across the plateau,with a spatial gradient reflecting decrease from the southeast toward the *** manifesting monotonous trends of increase or decrease in WUE accounted for 23.64%and 9.69%of the total,***,66.67%of the region exhibited trend reversals,i.e.,39.94%of the area of the Tibetan Plateau showed transition from a trend of increase to a trend of decrease,and 26.73%of the area demonstrated a shift from a trend of decrease to a trend of *** factors accounted for 70.79%of the variability in *** leaf area index and temperature served as the major driving forces of WUE variation.

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Preparation of high-purity straight silicon nanowires by molten salt electrolysis

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Journal of Energy Chemistry 2020年第1期29卷 171-179,I0006页

作者： Jie Zhang sheng Fang Xiaopeng qi Zhanglong Yu Zhaohui Wu Juanyu Yang Shigang lu General Research Institute for Nonferrous Metals Beijing 100088China China Automotive Battery Research Institute Co. LtdBeijing 100088China

Silicon nanowires of high purity and regular morphology are of prime importance to ensure high specific capacities of lithium-ion batteries and reproducible electrode assembly *** nickel formate as a metal catalyst precursor,straight silicon nanowires(65–150 nm in diameter)were directly prepared by electrolysis from the Ni/SiO2 porous pellets with 0.8 wt%nickel content in molten CaCl2 at 900℃.Benefiting from their straight appearance and high purity,the silicon nanowires therefore offered an initial coulombic efficiency of 90.53% and specific capacity of 3377 m Ah/*** addition,the silicon nanowire/carbon composite exhibited excellent cycle performance,retaining 90.38%of the initial capacity after 100 *** further study on the charge storage performance is still ongoing,these preliminary results demonstrate that nickel formate is an efficient and effective metal catalyst precursor for catalytic preparation of high purity straight silicon nanowires via the molten salt electrolysis,which is suitable for large-scale production.

关键词： Silicon nanowires Electrochemical reduction Silicon dioxide Nickel formate

Electrochemical synthesis of trimetallic nickel-iron-copper nanoparticles via potential-cycling for high current density anion exchange membrane water-splitting applications

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Journal of Energy Chemistry 2024年第2期89卷 535-542,I0012页

作者： Ziqi Zhang sheng Wan Hanbo Wang Jinghan He Ruige Zhang Yuhang qi Haiyan lu State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryJilin UniversityChangchun 130012JilinChina

Hydrogen is known for its elevated energy density and environmental compatibility and is a promising alternative to fossil *** water electrolysis utilizing renewable energy sources has emerged as a means to obtain high-purity ***,electrocatalysts used in the process are fabricated using conventional wet chemical synthesis methods,such as sol-gel,hydrothermal,or surfactantassisted approaches,which often necessitate intricate pretreatment procedures and are vulnerable to post-treatment ***,this study introduces a streamlined and environmentally conscious one-step potential-cycling approach to generate a highly efficient trimetallic nickel-iron-copper electrocatalyst in situ on nickel *** synthesized material exhibited remarkable performance,requiring a mere 476 mV to drive electrochemical water splitting at 100 mA cm^(-2)current density in alkaline ***,this material was integrated into an anion exchange membrane watersplitting device and achieved an exceptionally high current density of 1 A cm^(-2)at a low cell voltage of2.13 V,outperforming the noble-metal benchmark(2.51 V).Additionally,ex situ characterizations were employed to detect transformations in the active sites during the catalytic process,revealing the structural transformations and providing inspiration for further design of electrocatalysts.

关键词： Electrocatalytic water splitting Hydrogen evolution reaction Oxygen evolution reaction Electrochemical synthesis Anion exchange membrane

APPLET: a privacy-preserving framework for location-aware recommender system

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Science China(Information Sciences) 2017年第9期60卷 5-20页

作者： Xindi MA Hui LI Jianfeng MA qi JIANG sheng GAO Ning XI Di lu School of Computer Science and Technology Xidian University School of Cyber Engineering Xidian University School of Information Central University of Finance and Economics

Location-aware recommender systems that use location-based ratings to produce recommendations have recently experienced a rapid development and draw significant attention from the research ***, current work mainly focused on high-quality recommendations while underestimating privacy issues,which can lead to problems of privacy. Such problems are more prominent when service providers, who have limited computational and storage resources, leverage on cloud platforms to fit in with the tremendous number of service requirements and users. In this paper, we propose a novel framework, namely APPLET, for protecting user privacy information, including locations and recommendation results, within a cloud environment. Through this framework, all historical ratings are stored and calculated in ciphertext, allowing us to securely compute the similarities of venues through Paillier encryption, and predict the recommendation results based on Paillier,commutative, and comparable encryption. We also theoretically prove that user information is private and will not be leaked during a recommendation. Finally, empirical results over a real-world dataset demonstrate that our framework can efficiently recommend POIs with a high degree of accuracy in a privacy-preserving manner.

关键词： recommender system location-based service homomorphic encryption privacy-preserving frame work collaborative filtering

A study on the catalytic performance of carbide slag in transesterification and the calculation of kinetic parameters

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Science China(Technological Sciences) 2015年第2期58卷 258-265页

作者： LIU Meng qi NIU sheng Li lu Chun Mei LI Hui HUO Meng Jia School of Energy and Power Engineering Shandong University

The catalytic performance of carbide slag in transesterification is investigated and the reaction kinetic parameters are calculated. After being activated at 650℃, calcium compounds of carbonate and hydroxide in the carbide slag are mainly transformed into calcium oxide. The activated carbide slag utilized as the transesterification catalyst is characterized by X-ray diffraction （XRD）, attenuated total reflectance-Fourier transform infrared spectroscopy （ATR-FTIR）, nitrogen adsorption-desorption and the Hammett indicator method. Compared with the carbide slag activated at 700 and 800℃, the largest surface area of 22.63 m2g^-1, the smallest particle size of 265.12 nm and the highest catalytic efficiency of the carbide slag activated at 650℃ guarantee its capacity in catalyzing transesterification. Then, the influences of activated temperature （Ta）, molar ratio of methanol to oil （γ）, catalyst added amount （ζ）, reaction temperature （Tr） and reaction time （τ） on the catalytic performance are investi- gated. Under the optimal transesterification condition of Ta=650℃, γ=15, ζ=3%, Tr=60℃ and τ=-110 rain, the catalytic efficiency of 92.98% can be achieved. Finally, the kinetic parameters of transesterification catalyzed by the activated carbide slag are calculated, where activation energy （E） is 68.45 kJ mol^-1 and pre-exponential factor （k0） is 1.75×10^9 min^-1. The activated carbide slag shows better reused property than calcium hydroxide.

关键词： transesterification catalyst carbide slag kinetic parameters