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Characteristics and influencing factors of greenhouse gas emissions from reservoirs in the Yellow River Basin:A Meta-analysis

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Science China Earth Sciences 2024年第7期67卷 2210-2225页

作者： Shurui HUANG Peijia ZHANG wenxiu ZHENG Jiajia ZHANG Yang li Yuanjian WANG Enhui JIANG Shaoda liU Xinghui XIA State Key Laboratoy of Water Environment Simulation School of EnvironmentBeijing Normal UniversityBeijing 00875China Yellow River Institute of Hydraulic Research Yellow River Conservancy CommissionZhengzhou 450003China

Reservoir construction and operation profoundly alter the hydrological,hydrodynamic,and carbon and nitrogen cycling processes of rivers.However,current research still lacks a systematic understanding of the characteristics of greenhouse gas(GHG)emissions from reservoirs in arid/semi-arid regions.This study integrates existing monitoring data to discuss the characteristics of GHG emissions from reservoirs in the Yellow River Basin and illustrate the controlling factors and underlying mechanism of these processes.The results indicate that while CO_(2) emission flux from reservoirs is lower than that from river channels,the emission fluxes of CH_(4) and N_(2)O are 1.9 times and 10 times those from rivers,respectively,indicating that the emission of GHG with stronger radiative effect is significantly enhanced in reservoirs.Compared to the reservoirs in humid climates(e.g.,the Three Gorges Reservoir),reservoirs in the Yellow River Basin exhibit relatively lower emissions of CO_(2) and CH_4 due to lower organic matter concentrations,but significantly higher N_(2)O emissions due to higher nitrogen loads.Monte Carlo simulations for 237 reservoirs in the Yellow River Basin showed that total emission of the three GHGs is 3.05 Tg CO_(2)-eq yr^(-1),accounting for 0.39% of the total emission from global reservoirs and lower than the area percentage of the basin(0.53%).This study has important implications on revealing the GHG emission characteristics and control mechanisms of reservoirs in arid/semi-arid regions.

关键词： Yellow River Basin Reservoir Greenhouse gas Emission flux Water quality

Cysteine-activated fluorescence/photoacoustic integrated probe for non-invasive diagnosis of drug-induced liver injury

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Chinese Chemical Letters 2023年第5期34卷 484-488页

作者： Rui Chen wenxiu li Rong li Sixin Ai Huayong Zhu Weiying lin Guangxi Key Laboratory of Electrochemical Energy Materials Institute of Optical Materials and Chemical BiologySchool of Chemistry and Chemical EngineeringGuangxi UniversityNanning 530004China

Hepatotoxicity is a serious problem faced by clinical drugs,and long-term administration or overdose may lead to liver failure and even death of patients.Therefore,developing a reliable detection method for the early diagnosis and therapy of drug-induced liver injury(DIli)has significant meaning.Nearinfrared fluorescence(NIRF)and photoacoustic(PA)dual-modality tomography probes can be used for imaging with high sensitivity and high-resolution of disease-related markers in deep tissues.Here,we developed a novel Cys-activated NIRF and PA dual-modality imaging probe(CDR)for early diagnosis of DIli,for the first time.The organic molecular probe CDR could respond rapidly to Cys,resulting in the absorption peak red-shifted from 560 nm to 725 nm,which also leads to the activation of the PA725signal and NIRF765signal.In addition,the new probe CDR could be used for NIRF/PA imaging of exogenous and endogenous Cys level in live cells and mice.More importantly,CDR has also been successfully used for in situ detection of Cys in early DIli mice and evaluate the therapeutic effect of NAC.Therefore,the CDR might become a powerful tool to research the physiological effect of Cys and evaluate the degree of DIli.

关键词： Near-infrared fluorescence Photoacoustic imaging Fluorescence imaging Cysteine

Synthesis of ordered hierarchically mesoporous/microporous carbon materials via compressed CO_(2) for fructose-to-HMF transformation

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Green Energy & Environment 2022年第5期7卷 1033-1044页

作者： Sen Luan Wei li Zanwu Guo wenxiu li Xiaojian Hou Yi Song Ran Wang Qian Wang Department of Chemistry Capital Normal UniversityBeijing100048China

Well-ordered hierarchically mesoporous/microporous carbon materials have been successfully fabricated by using dual soft-templating approach through compressed CO_(2).Pluronic F127 and different type of surfactants,including nonionic,cationic,and anionic surfactants,were used as dual templates to investigate the influence on the morphology and nanostructure of the as-prepared carbon samples.TEM,SEM,N2 sorption,wide-angle and small-angle XRD analysis were employed to reveal the well-ordered hierarchically micro-mesoporous structure with2 D hexagonal symmetry by using compressed CO_(2).The prepared HPC samples with different pressures as the catalyst carriers have been functioned by chlorosulfonic acid for the fructose conversion into HMF.Chlorosulfonic acid concentration,catalyst dosage and reaction temperature have been optimized for fructose-to-HMF transformation with the obtained catalyst.The performances of as-made HPC-SO_(3) H samples in HMF yield and reaction rate of fructose-to-HMF transformation have been investigated.The stability of the samples was also conducted in the dehydration of fructose to HMF for five cycles.The possible catalytic mechanism by using hierarchically porous carbon materials as catalyst support for fructose-to-HMF transformation was proposed.

关键词： ordered catalyst carbon

大型游乐设施多姿态假人下肢省力驱动设计研究

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机械工程学报 2024年第1期60卷 352-360页

作者：李永辉卢文秀清华大学机械工程系北京100084 北京宇航系统工程研究所北京100076

为解决大型游乐设施传统检测方法可靠性低,进口假人与测试场景不匹配的问题,基于我国人体特征设计了多姿态假人下肢模型,以准确评估危险运行区间。对不同驱动模型进行运动学和动力学分析,基于Lagrange方程和动态静力分析法建立了驱动力... 详细信息

为解决大型游乐设施传统检测方法可靠性低,进口假人与测试场景不匹配的问题,基于我国人体特征设计了多姿态假人下肢模型,以准确评估危险运行区间。对不同驱动模型进行运动学和动力学分析,基于Lagrange方程和动态静力分析法建立了驱动力矩与腿部转动角度之间的关系,确定了下肢仿人1:1模型的低力矩驱动方案;利用传感器获取角度数据,分析了人体姿态调整规律,从而确定了下肢模型的运动参数,进一步通过微控制单元实时获取和调整模型姿态数据,实现了假人站姿和坐姿的转变。实验结果表明:间接驱动机构的驱动力矩约为直接驱动力矩的1/4,实现了低力矩电机驱动大力矩下肢模型;间接驱动模型主动构件运动非线性,通过轨迹规划结合PID控制实现了姿态调整过程的非线性驱动和平滑启停。

关键词：假人下肢模型力矩动态静力分析仿生机构轨迹规划

基于地理探测器的甘肃农牧交错带土地利用时空演化及其驱动机制

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干旱区研究 2024年第4期41卷 590-602页

作者：李文秀燕振刚甘肃农业大学理学院甘肃兰州730070 甘肃农业大学信息科学技术学院甘肃兰州730070

基于RS、GIS以及地理探测器,结合社会经济统计资料,对甘肃农牧交错带2000—2020年土地利用结构、动态度、利用程度和地类转移进行分析,并探究土地利用变化在不同时期的驱动因素。结果表明:(1)2000—2020年,甘肃农牧交错带以耕地、林地... 详细信息

基于RS、GIS以及地理探测器,结合社会经济统计资料,对甘肃农牧交错带2000—2020年土地利用结构、动态度、利用程度和地类转移进行分析,并探究土地利用变化在不同时期的驱动因素。结果表明:(1)2000—2020年,甘肃农牧交错带以耕地、林地和草地为主要用地类型,三者占比超过95%,土地利用结构差异度均小于0.01、结构总体趋于稳定,全域土地利用动态度总体呈先增加后放缓的趋势;(2)耕地、林地和草地的转化占研究区总体变化面积的96%以上,各地类间转换活跃,LUCC较集中分布于陇中黄土丘陵区和陇东黄土高原沟壑区;(3)在长时序土地利用变化情景下,地理探测器具有较好的适用性,甘肃农牧交错带土地利用变化在不同时段驱动因子相异,其变化受社会经济因素和自然地理因素共同作用驱动(前者对土地利用变化解释度更强),各因子间交互作用均表现为双因子增强或非线性增强效应,双因子交互对土地利用变化的解释度强于单因子解释度。

关键词：农牧交错带地理探测器土地利用时空演变驱动力甘肃

胞腔代数中的Rota-Baxter代数结构

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数学进展 2024年第1期53卷 133-141页

作者：李文秀李彦博东北大学理学院数学系辽宁沈阳110819 东北大学秦皇岛分校数学与统计学院河北秦皇岛066004

一个带有非平凡幂等元的结合代数带有自然的Rota-Baxter代数结构.本文研究胞腔代数的不同拟幂等元给出的Rota-Baxter结构间的同构关系.

关键词： Rata-Baxter代数 Temperley-lieb代数胞腔代数拟幂等元

Effect of methylimidazolium-based ionic liquids on vapor–liquid equilibrium behavior of tert-butyl alcohol + water azeotropic mixture at 101.3 kPa

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Chinese Journal of Chemical Engineering 2016年第3期24卷 365-372页

作者： Zhigang Zhang Qiang Zhang Tao Zhang Qinqin Zhang wenxiu li liaoning Provincial Key Laboratory of Chemical Separation Technology Shenyang University of Chemical Technology

Three ionic liquids(ILs),1-ethyl-3-methylimidazolium bromine([EMIM]Br),1-butyl-3-methylimidazolium bromine([BMIM]Br),and 1-hexyl-3-methylimidazolium bromine([HMIM]Br),were used as the solvent for separation of {tert-butyl alcohol(TBA)+ water} azeotrope.Vapor–liquid equilibrium(VLE)data for {TBA + water + IL}ternary systems were measured at 101.3 k Pa.The results indicate that all the three ILs produce an obvious effect on the VLE behavior of {TBA + water} system and eliminate the azeotropy in the whole concentration range.[EMIM]Br is the best solvent for the separation of {TBA + water} system by extractive distillation among the three ILs.The experimental VLE data for the ternary systems are correlated with the NRTL model equation with good correlations.Explanations are given with activity coefficients of water and TBA,and the experimental VLE-temperature data for {TBA or water + IL} binary systems.

关键词：汽液平衡共沸混合物离子液体叔丁醇 kPa 行为咪唑基水

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中国制造企业服务化转型的同群效应研究

技术经济 2024年第2期43卷 46-55页

作者：王思翔扈文秀李雷西安理工大学经济与管理学院西安710054

本文基于2007—2021年中国A股制造业上市公司样本数据,研究我国制造企业服务化转型同群效应的存在性、产生机制及其影响因素问题。结果表明,企业服务化转型存在地区同群效应,结论经过一系列稳健性检验后仍然成立。学习模仿是企业服务化... 详细信息

本文基于2007—2021年中国A股制造业上市公司样本数据,研究我国制造企业服务化转型同群效应的存在性、产生机制及其影响因素问题。结果表明,企业服务化转型存在地区同群效应,结论经过一系列稳健性检验后仍然成立。学习模仿是企业服务化转型同群效应的产生机制,市场竞争程度是影响服务化转型同群效应的重要因素。进一步研究发现,企业服务化转型的同群效应存在异质性,固定资产比重低或客户集中程度高的企业,开展服务化转型的同群效应更显著。

关键词：制造业企业服务化转型同群效应

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龙羊峡和刘家峡梯级水库生态流量核定与保障

南水北调与水利科技（中英文） 2024年第3期22卷 473-481页

作者：赵新磊李姝蕾尚文绣黄河勘测规划设计研究院有限公司郑州450003 水利部黄河流域水治理与水安全重点实验室(筹) 郑州450003

针对建设时间早、没有设置生态流量的梯级水库,提出生态流量核定方法:根据有关规范对生态流量的要求、水库主要影响河段已批复的流量控制指标和水库已有调度任务下泄需求得到生态流量初值,通过梯级水库调度模拟模型和历史长系列实测出... 详细信息

针对建设时间早、没有设置生态流量的梯级水库,提出生态流量核定方法:根据有关规范对生态流量的要求、水库主要影响河段已批复的流量控制指标和水库已有调度任务下泄需求得到生态流量初值,通过梯级水库调度模拟模型和历史长系列实测出库径流过程分析水库对生态流量的保障能力,提出生态流量推荐值。以黄河上游龙羊峡水库和刘家峡水库为研究对象核定生态流量,结果显示:龙羊峡水库生态流量5—6月为400 m^(3)/s、其他时段为200 m^(3)/s,刘家峡水库生态流量为285 m^(3)/s,长期保证率均不低于90%。龙羊峡水库和刘家峡水库对生态流量均有较好的保障能力,但是极端枯水条件下龙羊峡水库敏感期生态流量保障仍面临风险。

关键词：生态流量已建水库梯级水库多任务协调龙羊峡水库刘家峡水库黄河