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不平衡输沙条件下河道断面形态调整规律试验研究

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人民黄河 2024年第9期46卷 127-131页

作者：杨芬娇韩沙沙赵连军常奥郑州大学水利与交通学院河南郑州450001 黄河水利委员会黄河水利科学研究院河南郑州450003 水利部黄河下游河道与河口治理重点实验室河南郑州450003

21世纪以来,受气候变化与人类活动共同影响,进入黄河下游河道的水沙条件发生显著变化,下游河道长期处于不平衡输沙状态,横断面形态调整剧烈,直接影响河势稳定,威胁下游防洪安全。基于2001—2021年黄河下游白鹤镇—高村河段实测断面资料... 详细信息

21世纪以来,受气候变化与人类活动共同影响,进入黄河下游河道的水沙条件发生显著变化,下游河道长期处于不平衡输沙状态,横断面形态调整剧烈,直接影响河势稳定,威胁下游防洪安全。基于2001—2021年黄河下游白鹤镇—高村河段实测断面资料,在分析原型河道横断面形态参数演变特征的基础上,选取黑岗口—柳园口河段开展物理模型试验,以定量揭示不平衡输沙条件下横断面形态调整规律。原型实测资料分析发现,相对于黄河下游其他河段,花园口—夹河滩河段断面形态变化相对较大。选择花园口—夹河滩河段中典型河段为原型,采用水平比尺600、垂直比尺60构建物理模型,保持相同的初始河道边界条件,开展了2000、3000、4000、5000 m^(3)/s四级流量,不同进口含沙量条件下断面形态调整试验。试验结果表明,各测验断面基本呈现进口含沙量较小时主槽冲刷、面积增大、河相系数减小,进口含沙量较大时主槽淤积、面积减小、河相系数增大的规律。对比原型资料与试验数据发现,不平衡输沙条件下,河段尺度的断面形态参数与来沙系数相关性较好,其中主槽面积与来沙系数成指数负相关,河相系数与来沙系数成二次函数关系。

关键词：横断面形态调整不平衡输沙物理模型试验黄河下游

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智慧居家养老服务用户使用意愿影响因素研究

长春师范大学学报 2024年第3期43卷 54-63页

作者：孙长智赵艳蕊武长奥长春工业大学公共管理学院吉林长春130012

为探析影响老年用户对智慧居家养老服务使用意愿的因素,基于UTAUT模型、信任理论、感知风险理论与相关文献,提出研究假设,通过调研收集数据,运用AMOS26.0构建结构方程模型,进行假设检验。结果显示,绩效期望、努力期望、社会影响、便利... 详细信息

为探析影响老年用户对智慧居家养老服务使用意愿的因素,基于UTAUT模型、信任理论、感知风险理论与相关文献,提出研究假设,通过调研收集数据,运用AMOS26.0构建结构方程模型,进行假设检验。结果显示,绩效期望、努力期望、社会影响、便利条件、感知信任正向影响老年人使用智慧居家养老服务的意愿;感知风险负向影响老年人使用智慧居家养老服务的感知信任与使用意愿;感知信任在感知风险与使用意愿之间起部分中介作用。结合研究结论,提出丰富智慧居家养老服务内容、推动服务适老化、扩宽宣传渠道、创造便利条件、完善保障体系五方面建议,以期提升智慧居家养老服务用户的使用意愿。

关键词：智慧居家养老服务老年用户使用意愿影响因素

Sensitivity analysis of the SWAP(Soil-Water-Atmosphere-Plant)model under different nitrogen applications and root distributions in saline soils

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Pedosphere 2021年第5期31卷 807-821页

作者： Guoqing LEI Wenzhi ZENG Yonghua JIANG chang ao Jingwei WU Jiesheng HUANG State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072(China) School of Remote Sensing and Information Engineering Wuhan UniversityWuhan 430079(China) State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan 430079(China)

Sensitivity analysis is important for determining the parameters in the model calibration *** our study,a variance-based global sensitivity analysis(extended Fourier amplitude sensitivity test,EFAST)was applied to an agro-hydrological model(the SWAP(Soil-Water-Atmosphere-Plant model)model).The sensitivities of 20 parameters belonging to 4 categories(soil hydraulics,solute transport,root water uptake,and environmental stresses)for the simulated accumulated transpiration,dry matter(DM),and yield of sunflowers were analyzed under three nitrogen application rates(N1,N2,and N3),four salinity levels(S1,S2,S3,and S4),and three root distributions(R1,R2,and R3).The results indicated that for predominantly loamy soils,the high-impact parameters for accumulated transpiration,DM,and yield were the soil hydraulic parameters(αand n),critical stress index for compensatory root water uptake(ωc),the salt level at which salt stress starts(Pi),the decline of root water uptake above Pi(SSF),residual water content(θr),saturated water content(θs),and relative uptake of solutes by roots(TSCF).We also found that nitrogen application did not change the order of the parameter impacts on accumulated transpiration,DM,and ***,TSCF replacedαas the highest-impact parameter for the accumulated transpiration,DM,and yield at high salinity levels(S2 and S3).Furthermore,αwas also the highest-impact parameter for DM and yield under different root distributions,but the highest-impact parameters for transpiration wereωc,α,andθs under R1,R2,and R3,*** application could be neglected when considering the interactive effects of nitrogen application,salinity level,and root distribution on the transpiration,DM,and ***,the mean values and uncertainties of the transpiration,DM,and yield were similar in all scenarios,except S3,which showed a sharp decrease in the mean *** suggest determining the above eight parameters(α,n,ωc,Pi,SSF,θr,θs,and TSCF)and the sat

关键词： accumulated transpiration agro-hydrological model dry matter hydraulic parameter sunflower yield

基于Sentinel-2卫星影像和土壤变量的盐渍化土壤水溶性盐基离子含量反演

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中国农村水利水电 2024年第7期 210-217,228页

作者：谭旺刘义董建华杨阳黄介生敖畅曾文治武汉大学水利水电学院湖北武汉430072 河海大学农业科学与工程学院江苏南京211100

本研究旨在探讨结合多光谱遥感技术和土壤物理化学属性进行土壤水溶性离子含量预测的可行性。研究区域位于新疆南部的盐渍化土壤区域,测定土壤中主要水溶性盐基离子含量(K^(+)、Na^(+)、Ca^(2+)、Mg^(2+)、HCO_(3)^(-)、Cl^(-)、SO_(4)^... 详细信息

本研究旨在探讨结合多光谱遥感技术和土壤物理化学属性进行土壤水溶性离子含量预测的可行性。研究区域位于新疆南部的盐渍化土壤区域,测定土壤中主要水溶性盐基离子含量(K^(+)、Na^(+)、Ca^(2+)、Mg^(2+)、HCO_(3)^(-)、Cl^(-)、SO_(4)^(2-)),并应用随机森林(Random Forest,RF),梯度提升回归树(Gradient Boosting Regression,GBR)和极端梯度提升(Extreme gradient boosting,XGBoost)3种机器学习算法构建基于遥感光谱特征及土壤信息的土壤离子含量反演模型,同时对比了纳入与未纳入土壤变量的模型预测精度。结果表明:仅使用多光谱遥感数据作为输入变量时,3种模型均仅能区分土壤离子含量的高低水平,但对各离子含量进行精确预测的能力有限。将土壤变量纳入模型后,预测精度均得到显著提升。在所选用的3种方法中,随机森林模型的预测精度最高,XGBoost次之,GBR模型的精度最低。就各个离子的预测而言,Mg^(2+)、Ca^(2+)和Na^(+)含量的预测精度较高且模型表现较为稳定;SO_(4)^(2-)、Cl^(-)和K^(+)的预测表现一般,具备定量预测能力;而HCO_(3)^(-)含量的预测仅GBR模型具有一定程度的可行性。不同离子的最优预测模型存在差异,其中随机森林模型对K^(+)、Mg^(2+)和Cl^(-)三种离子的反演效果最佳;XGBoost模型在Ca^(2+)、Na^(+)和SO_(4)^(2-)三种离子的反演中表现为最优;GBR模型则在HCO_(3)^(-)离子反演中展现了较好的性能。特别地,Mg^(2+)、Ca^(2+)和Na^(+)含量的最优相对分析误差分别为2.829、1.951和1.870,说明这些模型对于这3种离子含量的预测具有较高的可靠性。研究成果可以为干旱区土壤盐分主要离子含量的区域尺度预测提供科学参考。

关键词：土壤盐渍化盐基离子 Sentinel-2 机器学习反演模型

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基于生态安全的毛乌素沙地水资源承载力评价

节水灌溉 2024年第5期 28-37页

作者：唐古藞山陈皓锐鹿海员郑和祥田小强敖畅曾文治武汉大学水利水电学院武汉430072 中国水利水电科学研究院北京100038 水利部牧区水利科学研究所呼和浩特010013 鄂尔多斯市水旱灾害防御技术中心内蒙古鄂尔多斯017000 河海大学农业科学与工程学院南京210024

毛乌素沙地地区作为我国生态治理成功有效的典型区域,相较于其他主要沙漠、沙地而言,具有资源丰富、水热配合好等优点,同时也是受到人类活动及气候变化威胁较大的生态脆弱区,如何保障生态安全的同时协调社会经济高质量发展,成为了当地... 详细信息

毛乌素沙地地区作为我国生态治理成功有效的典型区域,相较于其他主要沙漠、沙地而言,具有资源丰富、水热配合好等优点,同时也是受到人类活动及气候变化威胁较大的生态脆弱区,如何保障生态安全的同时协调社会经济高质量发展,成为了当地所需解决的首要难题。以内蒙古鄂尔多斯毛乌素沙地地区为研究对象,构建基于生态安全的综合水资源承载力评价体系,运用投影寻踪法计算综合水资源承载力评价值,引入障碍度模型遴选地区承载力优势指标与劣势指标,采用耦合协调度模型测算资源-生态-社会系统耦合发展现状。结果表明:2000年至今毛乌素沙地地区的水资源承载力总体时间上呈现曲折上升趋势,但仍有提升空间,在空间上形成了“南北高,中心低”的空间分布特点,期间地下水供水能力、灌溉水利用系数和三产用水定额等是水资源承载力系统的主要“优势指标”,而人口、灌溉面积以及城镇化率则是阻碍水资源承载力提升的关键“劣势指标”,地区内各旗县耦合协调度从“十五”规划至今一直在中等水平范围内浮动。

关键词：毛乌素沙地水资源承载力评价投影寻踪法生态安全障碍度模型耦合协调度模型水资源-社会经济-生态环境

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《营养与健康》课程教学改革

饮料工业 2024年第4期27卷 50-53页

作者：刘卫华赵仁邦王向红汤轶伟敖常伟河北农业大学食品科技学院河北保定071000

《营养与健康》这门通识选修课在我校虽已开设多年,但存在着课程目标单一、教学内容照搬教材、教学方法和考核方式单调等问题。针对这些问题,重构了教学目标、整合了教学内容,全程融入思政教育元素,采用多媒体结合智慧教学工具、联系中... 详细信息

《营养与健康》这门通识选修课在我校虽已开设多年,但存在着课程目标单一、教学内容照搬教材、教学方法和考核方式单调等问题。针对这些问题,重构了教学目标、整合了教学内容,全程融入思政教育元素,采用多媒体结合智慧教学工具、联系中华饮食文化、引入最新科研成果、联系时事热点、结合实际生活等多种教学方式方法,同时加强过程管理,完善课程考核评价体系。教学改革后,强化了学生的思想政治教育,调动了学习的积极性和学习兴趣,提升了学生对课程知识的整体性建构,提高了学习成绩和知识应用能力,得到了学生的普遍好评和认可。

关键词：营养与健康教学改革教学研究课程育人

Polymer Photovoltaic Cells

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复旦学报（自然科学版） 2005年第5期44卷 717-718页

作者： Jianhui Hou Chunhe Yang Erjun Zhou chang He Zhan＇ ao Tan Youjun He Yongfang Li CAS Key Laboratory of Organic Solids Center for Molecular Science Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

Polymer photovoltaic cells (PPVCs) have attracted much attention recently because of its easy fabrication, low cost and possibility to make flexible devices[1]. PPVC is composed of a conjugated polymer/C60blend layer (photosensitive layer) sandwiched between a transparent ITO electrode and a metal *** a light through ITO electrode irradiates on the photosensitive layer, the photons with appropriate energy will be absorbed by the conjugated polymer (CP) and excitons (electron-hole pair) are produced. The excitons move to the interface of CP/C60 where the electrons transfer to the LUMO of C60 and holes leave on the HOMO of the CP. The separated electrons migrate through the C60 network to and are collected by the metal electrode, and the holes migrate through the CP network to and are collected by the ITO electrode, so that the photocurrent and photovoltage are attained.

关键词：光电电池共轭聚合体太阳能电池电极电解液

Effect of MgO-Cr_(2)O_(3) and Mg0-MgAl_(2)0_(4)-based refractories on refractory-steel interface reaction and cleanliness of pipeline steel

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Journal of Iron and Steel Research International 2024年第4期31卷 849-860页

作者： Guang-mei Yang Cheng Yuan chang Liu Qiang Wang Guang-qiang Li Yong-shun Zou ao Huang The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina

The interaction of MgO-MgAl_(2)O_(4)-based and MgO-Cr_(2)O_(3)-based refractories with X70 molten steel was studied by immersion experiments at 1560℃.The effects of immersion time(30 and 60 min)on the contents of total oxygen(TO),Al,Nb,Si,Mn,and Cr as well as the composition,number density,and size distribution of inclusions in the molten steel were *** influence of the penetration and erosion degree of the molten steel to the refractory on the steel-refractory interface layer was *** results show that,at 1560℃,the MgO-MgAl_(2)O_(4)-based refractory can better control the contents of TO and the composition of molten steel compared with the MgO-Cr_(2)O_(3)-based *** TO content is only 16×10^(-4) wt.%in the molten steel after reacted with the Mg0-MgAl_(2)O_(4)-based refractory at the end point of refining,4 accounting for 11.5%of that reacted with the MgO-Cr_(2)O_(3)-based refractory(139×10^(-4) wt.%).The number density of inclusions is only 14 mm^(-2),and the average size ofinclusions is only 1.31μm,with thelargest proportion of inclusions in 1-2μm(70%).The Al_(2)O_(3)-MnS-Cao complex inclusions in the original steel changed to complex inclusions dominated by Cr-Nb-Mn-S-O and ***_(2)O_(3),corresponding to the MgO-Cr_(2)O_(3)-based and MgO-MgAl_(2)O_(4)-based refractories,*** ***_(2)O_(3) layer was formed at the reaction interface between MgO-MgAl_(2)O_(4)-based refractory and molten steel,which is helpful to restrict the erosion of refractories and the pollution of molten *** damage mechanism of the MgO-Cr_(2)O_(3)-based refractory is mainly permeation and chemical reaction,while the damage of the MgO-MgAl_(2)O_(4)-based refractory is mainlyscouring erosion.

关键词： MgO-Cr_(2)O_(3)-based refractory MgO-MgAl O_(4)-based refractory Nonmetallic inclusion Erosion interface layer Steel penetration

Original article： Arthroscopic treatment for osteochondral lesions of the talus： analysis of outcome predictors

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Chinese Medical Journal 2010年第3期 296-300页

作者： GUO Qin-wei HU Yue-lin JIao Chen YU chang-long ao Ying-fang Institute of Sports Medicine Peking University Third Hospital Beijing 100191 China

Background Compared with traditional arthrotomy procedures, arthroscopic treatment for osteochondral lesions of the talus has some advantages. However, there has been considerable debate about the outcome predictors for this surgical technique. This study aimed to investigate the outcomes of arthroscopic treatment for osteochondral lesions of the talus, and analyze its outcome predictors. Methods Clinical data of 48 patients with osteochondral lesions of the talus who underwent ankle arthroscopy were studied. Arthroscopic debridement was performed on all patients, and microfracture was also performed in 36 cases. Scores on a subjective satisfaction questionnaire, visual analog scale （VAS） for pain, and the American Orthopedic Foot ＆ Ankle Society （aoFAS） ankle and hindfoot scores were obtained before and after surgery. Results Five patients lost to follow up. The other forty-three patients, 8 of whom were athletes, were followed up for an average of 23.9 months. The average aoFAS post-operative score was 90.16±9.96, compared with 70.81±6.96 before surgery （t=9.353, P 〈0.001）. The VAS pain score after the operation （2.51±2.45） was significantly lower than that before the operation （6.95±.40）（t=8.647, P 〈0.001 ）. Of the 43 patients, 35 （81.4%） had good or excellent results. There was no significant difference in outcome between the medial and lateral groups （z=0.205, P=0.838）, while a better outcome was found with lesions smaller than 10 mm than those with larger lesions （z=2.199, P=0.028）. Age, sex, athletic profession and location of the lesion did not significantly correlate with outcomes. Conclusions Arthroscopic treatment is effective and safe for osteochondral lesions of the talus. A strong correlation was found between the size of the lesion and successful outcome.

关键词： osteochondral lesion talus arthroscopy