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Journal of Ocean University of China 2024年第5期23卷 1173-1184页

作者： DONG Sheng li songda TAO Shanshan College of Engineering Ocean University of ChinaQingdao 266404China

Owing to climate change and human activity,the Qingshuigou of the Yellow River Delta(YRD)has undergone dynamic changes in erosion and ***,studying these changes is important to ensure ecological protection and sustainable *** this study,the trend of erosion-deposition evolution in the Qingshuigou was investigated based on 38 coastline phases extracted from Landsat series images of the YRD at one-year intervals from 1984 to *** periodicity of the scouring and deposition evolution was also analyzed using wavelet *** showed that the total area of the Qingshuigou was affected by deposition and erosion and that the fluctuation first increased and then *** total area reached a maximum in *** depositional area first increased and then decreased,whereas the overall erosion area *** and erosion areas showed periodic changes to some extent;however,the periodic signal intensity ***,factors including channel morphological evolution and variations in water and sediment discharge affect the spatiotemporal dynamics of erosion and deposition *** application of nonconsistency tests finally revealed that deposition area and flushing magnitude exhibited non-stationarities,which are potentially attributed to impacts from climatic change drivers.

关键词： Yellow River Delta coastline erosion and deposition remote sensing wavelet analysis

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5-羟甲基糠醛的急性毒性研究

饲料工业 2024年第18期45卷 83-92页

作者：李松达崔洪伟王昭华邵明珠安乐乐李松励中国农业科学院北京畜牧兽医研究所北京100193

实验旨在研究5-羟甲基糠醛(5-HMF)对昆明小鼠的急性毒性影响,初步评价产品对昆明小鼠的毒效应特征、靶器官和剂量-反应关系。选取80只SPF级雄性昆明小鼠,随机分为8组,每组10只。适应性饲养一周后,采用8种不同剂量的5-HMF溶液进行口服灌... 详细信息

实验旨在研究5-羟甲基糠醛(5-HMF)对昆明小鼠的急性毒性影响,初步评价产品对昆明小鼠的毒效应特征、靶器官和剂量-反应关系。选取80只SPF级雄性昆明小鼠,随机分为8组,每组10只。适应性饲养一周后,采用8种不同剂量的5-HMF溶液进行口服灌胃。结果表明,昆明小鼠灌胃给药后随剂量增加出现呼吸困难、急促,扎堆、眯眼,被毛竖立而后死亡,随着剂量降低,出现以上现象频率降低。体重方面,与对照组相比,药物对体重无明显影响。利用改良寇式法计算昆明小鼠5-HMF急性毒性LD_(50)为3152.800 mg/kg。存活动物组织病理学检查结果显示:5-HFM毒性靶向器官为肾脏,小叶间静脉旁间质见炎性细胞浸润。根据WHO口服外源毒物分级标准,5-HMF为低毒。

关键词： 5-羟甲基糠醛急性毒性毒效应特征昆明小鼠炎性细胞

Array of single crystalline anatase TiO2 nanotubes with significant enhancement of photoresponse

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Progress in Natural Science:Materials International 2021年第4期31卷 536-540页

作者： Lvchao Qiu Ke Fang Yubo li Shutao Huang Guanxing li songda li Hu He Wentao Yuan Hangsheng Yang Wei Tian Yong Wang State Key Laboratory of Silicon Materials School of Materials Science and Engineering Zhejiang University Center of Electron Microscopy School of Materials Science and Engineering Zhejiang University Key Laboratory of Micro-Nano Electronic Device and Smart System of Zhejiang Province College of Information Science & Electronic Engineering Zhejiang University School of Physical Science and Technology Soochow University

Anatase TiO2nanotubes array(ATONA) has attracted tremendous attention owing to its promising applications in solar cells, water splitting and organic pollutants photocatalytic degradation. However, the activity of ATONAs was greatly suppressed by the grain boundaries existed in the tube walls, which acted as carrier scattering and recombination centers. Herein, we report a novel strategy to prepare array of single crystalline anatase TiO2nanotubes(SC-ATONAs) with significant enhancement of the photocatalytic activity and UV photo response performance compared to the polycrystalline counterparts. The growth of SC-ATONAs was achieved by establishing a crystallization temperature gradient along the tube wall, which ensured the crystallization started from the nucleation of a single nucleus at the bottom of amorphous TiO2nanotubes prepared by Ti anodization. These findings pave the way to prepare single-crystalline nanotubes with superior performance for other materials.

关键词： Single crystalline TiO 2 nanotube Crystallization temperature gradient Photo response Photocatalysis

Mechanistic insight into N_2O formation during NO reduction by NH_3 over Pd/CeO_2 catalyst in the absence of O_2

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Chinese Journal of Catalysis 2019年第7期40卷 1070-1077页

作者： liping Sheng Zhaoxia Ma Shiyuan Chen Jinze Lou Chengye li songda li Ze Zhang Yong Wang Hangsheng Yang State Key Laboratory of Silicon Materials and Center of Electron Microscopy School of Materials Science and EngineeringZhejiang UniversityHangzhou310027ZhejiangChina

N2O is a major by-product emitted during low-temperature selective catalytic reduction of NO with NH3(NH3-SCR), which causes a series of serious environmental problems. A full understanding of the N2O formation mechanism is essential to suppress the N2O emission during the low-temperature NH3-SCR, and requires an intensive study of this heterogeneous catalysis process. In this study, we investigated the reaction between NH3 and NO over a Pd/CeO2 catalyst in the absence of O2, using X-ray photoelectron spectroscopy, NH3-temperature-programmed desorption, NO-temperature-programmed desorption, and in-situ Fourier-transform infrared spectroscopy. Our results indicate that the N2O formation mechanism is reaction-temperature-dependent. At temperatures below 250 ℃, the dissociation of HON, which is produced from the reaction between surface H· adatoms and adsorbed NO, is the key process for N2O formation. At temperatures above 250 ℃,the reaction between NO and surface N·, which is produced by NO dissociation, is the only route for N2O formation, and the dissociation of NO is the rate-determining step. Under optimal reaction conditions, a high performance with nearly 100% NO conversion and 100% N2 selectivity could be achieved. These results provide important information to clarify the mechanism of N2O formation and possible suppression of N2 O emission during low-temperature NH3-SCR.

关键词： N2O formation NO reduction Pd/CeO2 catalyst in-situ IR spectroscopy Mechanism

Reversible transformation between terrace and step sites of Pt nanoparticles on titanium under CO and O_(2) environments

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Chinese Journal of Catalysis 2022年第8期43卷 2026-2033页

作者： Yang Ou songda li Fei Wang Xinyi Duan Wentao Yuan Hangsheng Yang Ze Zhang Yong Wang Center of Electron Microscopy and State Key Laboratory of Silicon Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027ZhejiangChina Key Laboratory of Interfacial Physics and Technology Shanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai 201800China c University of Chinese Academy of Science Beijing 100049China

Understanding the dynamic evolution of active sites of supported metal catalysts during catalysis is fundamentally important for improving its performance,which attracts tremendous research interests in the past *** are two main surficial structures for metal catalysts:terrace sites and step sites,which exhibit catalytic activity discrepancy during ***,by using in situ transmission electron microscopy and in situ Fourier transform infrared spectroscopy(FTIR),the transformation between surface terrace and step sites of Pt-TiO_(2) catalysts was studied under CO and O_(2) *** found that the{111}step sites tend to form at{111}terrace under O_(2) environment,while these step sites prefer to transform into terrace under CO environment at elevated ***,quantitative ratios of terrace/step sites were obtained by in situ *** was found that this transformation between terrace sites and step sites was reversible during gas treatment cycling of CO and O_(2).The selective adsorption of O_(2) and CO species at different sites,which stabilized the step/terrace sites,was found to serve as the driving force for active sites transition by density functional theory *** by the in situ results,an enhanced catalytic activity of Pt-TiO_(2) catalysts was successfully achieved through tuning surface-active sites by gas treatments.

关键词： In situ transmission electron microscopy Surface reconstruction Metal catalyst Active site CO oxidation reaction

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片段级别的双编码器方面情感三元组抽取模型

计算机科学与探索 2023年第12期17卷 3010-3019页

作者：张韵琪李松达兰于权李东旭赵慧华东师范大学软件工程学院上海200062 华东师范大学上海市高可信计算重点实验室上海200062

方面情感三元组抽取(ASTE)是方面级情感分析的子任务之一,旨在识别出句子中所有的方面词及其对应的观点词和情感极性。目前,ASTE任务通过流水线模型或端到端模型完成,前者无法解决三元组方面词重叠问题,且忽视了观点词和情感极性之间的... 详细信息

方面情感三元组抽取(ASTE)是方面级情感分析的子任务之一,旨在识别出句子中所有的方面词及其对应的观点词和情感极性。目前,ASTE任务通过流水线模型或端到端模型完成,前者无法解决三元组方面词重叠问题,且忽视了观点词和情感极性之间的依赖关系;后者将ASTE任务分解为方面词和观点词抽取子任务以及情感极性分类子任务,通过共享编码器进行多任务学习,未区分两个子任务的特征差异,导致特征混淆问题。针对上述问题,提出了片段级别的双编码器方面情感三元组抽取模型(SD-ASTE)。该模型是流水线模型,分为两个模块。第一个模块基于片段抽取方面词和观点词,在片段特征表示中融入片段首尾和长度信息,关注方面词和观点词的边界信息;第二个模块判断方面词-观点词片段对表达的情感极性,采用基于悬浮标记的片段对特征表示方式,侧重于学习三元组各元素之间的依赖关系。模型利用两个独立编码器,分别为两模块提取不同的特征信息。多个数据集上的对比实验结果表明,该模型相较于目前最优的流水线模型和端到端模型具有更优的效果。通过有效性实验,验证了片段特征表示和片段对特征表示以及两个独立编码器的有效性。

关键词：情感分析方面情感三元组抽取(ASTE) 流水线模型片段独立编码器

印度莫迪政府反恐政策工具化转向——基于新古典现实主义的解释

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南亚研究 2024年第2期 123-152,157,158页

作者：李益斌胡宋达兰州大学印度研究中心兰州大学政治与国际关系学院

近年来印度国内的恐怖主义活动整体有所缓和,但莫迪政府的反恐政策却呈现出更加显著的工具化转向,此现象值得深入探究.本文借助第三类新古典现实主义模型搭建解释框架,将中美印互动的刺激作为自变量,因变量为印度反恐政策工具化,中巴合... 详细信息

近年来印度国内的恐怖主义活动整体有所缓和,但莫迪政府的反恐政策却呈现出更加显著的工具化转向,此现象值得深入探究.本文借助第三类新古典现实主义模型搭建解释框架,将中美印互动的刺激作为自变量,因变量为印度反恐政策工具化,中巴合作深化和巴基斯坦国内恐怖主义的复杂性是结构性调节因素,而印度国内决策层和社会层的四个支持因素是中介变量.该解释框架连接起印度国内政治与国际体系二者的关系,表明莫迪政府反恐政策工具化不仅意在实现对国内资源的控制与整合,而且更是为了满足其对全球性领导大国地位的追求.根据该解释框架,2024年印度大选后印度反恐政策的工具化转向不会出现明显收缩,甚至有持续强化的可能.这对印度国内宗教矛盾、南亚地区安全形势以及中国海外利益保护均产生不容忽视的影响.

关键词：莫迪政府反恐政策反恐工具化新古典现实主义

MnO_(x)-CeO_(2)催化剂中元素价态对低温SCR还原NO_(x)性能的影响

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材料科学与工程学报 2023年第6期41卷 869-877,896页

作者：郑拓王飞李松达郑红梅张彦张玉郭成成张凯邵博赵志浩王勇杨杭生浙江大学硅及先进半导体材料全国重点实验室材料科学与工程学院浙江杭州310027 浙江大学电子显微镜中心硅及先进半导体材料全国重点实验室材料科学与工程学院浙江杭州310027 浙江巨化技术中心有限公司浙江衢州324004 浙江衢化氟化学有限公司浙江衢州324004 浙江巨化环保科技有限公司浙江衢州324004

采用具有MOFs结构的Ce-MOFs作为前驱体,制备了一系列不同Ce4+离子浓度的CeO_(2),然后负载MnO_(x)制备MnO_(x)-CeO_(2)催化剂,研究发现热处理工艺可以有效调控催化剂中Mn元素和Ce元素的化合价,从而调控催化活性。其中700℃焙烧的CeO_(2)... 详细信息

采用具有MOFs结构的Ce-MOFs作为前驱体,制备了一系列不同Ce4+离子浓度的CeO_(2),然后负载MnO_(x)制备MnO_(x)-CeO_(2)催化剂,研究发现热处理工艺可以有效调控催化剂中Mn元素和Ce元素的化合价,从而调控催化活性。其中700℃焙烧的CeO_(2)载体负载MnO_(x)后经过300℃热处理制备的催化剂,具有最高脱硝活性,在150~200℃的温度区间NO_(x)转化率接近100%。X射线衍射(XRD)、扫描电镜(SEM)、NH_(3)程序升温脱附(NH_(3)-TPD)、NO温度程序脱附(NO-TPD)等分析显示,在MnO_(x)-CeO_(2)催化剂上SCR脱硝反应主要遵循L-H路径,催化剂中的高浓度Ce^(4+)离子、Mn^(2+)离子和Mn^(3+)离子,有利于催化剂的低温SCR脱硝活性,而Mn4+离子并不是催化剂的最佳活性成分。

关键词：氮氧化物低温选择性催化还原锰铈催化剂活性位点 MOF前驱体

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双烷基脲稠化烃基压裂液的制备及其流变特性

中国石油大学学报（自然科学版） 2022年第4期46卷 123-129页

作者：魏志毅张金泽公证刘崧达刘佳音李家豪范海明中国石油大学(华东)石油工程学院山东青岛266580 山东省油田化学重点实验室(中国石油大学(华东)) 山东青岛266580

以烷基胺与二异氰酸酯为原料反应制备双烷基脲稠化剂,无需交联即可通过分子自组装的方式使烷烃稠化,分析反应原料对双烷基脲稠化效果的影响,研究稠化烃基压裂液体系的流变特性和耐温性能。结果表明:2-乙基己胺与2,4-甲苯二异氰酸酯反应... 详细信息

以烷基胺与二异氰酸酯为原料反应制备双烷基脲稠化剂,无需交联即可通过分子自组装的方式使烷烃稠化,分析反应原料对双烷基脲稠化效果的影响,研究稠化烃基压裂液体系的流变特性和耐温性能。结果表明:2-乙基己胺与2,4-甲苯二异氰酸酯反应得到的2,4-二(乙基己基脲基)甲苯(EHUT)对烷烃的稠化效果最优,随着烷烃碳数、稠化剂浓度的增加而提高;EHUT稠化烃基压裂液的静态流变曲线表现出牛顿体-剪切变稀的特征,动态流变曲线表现出弹性和黏性模量仅有一个交点且在低振荡角频率下基本符合Maxwell型流体的特征,这些流变特性与由蠕虫状胶束形成的黏弹性表面活性剂压裂液体系的流变特性一致,表明体系中小分子在非共价键作用下形成超分子聚集体并相互缠结而呈三维网络结构;由于温度升高会破坏EHUT分子间氢键相互作用,削弱形成超分子聚集体的重要驱动力,因此质量分数为1%的EHUT稠化正庚烷压裂液170 s^(-1)时的表观黏度在60℃降低至20 mPa·s。

关键词：双烷基脲烃基压裂液分子自组装流变特性耐温性

维普期刊数据库博看期刊

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含醇交联压裂液的交联和耐温性能

中国石油大学学报（自然科学版） 2021年第6期45卷 120-126页

作者：范海明杨航李玲玉魏志毅张随望张金泽刘崧达杨红斌山东省油田化学重点实验室中国石油大学(华东)石油工程学院山东青岛266580 长庆油田公司油气工艺研究院陕西西安710018

研究瓜胶(GG)、羟丙基瓜胶(HPG)和羧甲基羟丙基瓜胶(CMHPG)在不同乙醇含量下的溶解性能,并以四硼酸钠为交联剂制备含醇交联压裂液体系,分析交联性能和耐温性能随乙醇体积分数的变化。结果表明:瓜胶、羟丙基瓜胶和羧甲基羟丙基瓜胶分别... 详细信息

研究瓜胶(GG)、羟丙基瓜胶(HPG)和羧甲基羟丙基瓜胶(CMHPG)在不同乙醇含量下的溶解性能,并以四硼酸钠为交联剂制备含醇交联压裂液体系,分析交联性能和耐温性能随乙醇体积分数的变化。结果表明:瓜胶、羟丙基瓜胶和羧甲基羟丙基瓜胶分别在乙醇体积分数为10%、50%和60%时可以充分溶解;加入交联剂四硼酸钠后,羟丙基瓜胶和羧甲基羟丙基瓜胶可在乙醇体积分数分别不超过30%和50%形成含醇交联压裂液;由于乙醇具有抑制瓜胶类稠化剂分子链降解和增强交联程度的双重作用,含醇压裂液具有比水基压裂液更强的耐温性能。

关键词：含醇压裂液改性瓜胶交联耐温性