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Hydrothermally stable metal oxide-zeolite composite catalysts for low-temperature NO_(x) reduction with improved N_(2) selectivity

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Chinese Chemical Letters 2024年第6期35卷 515-523页

作者： Lijun yan Shiqi Chen Penglu Wang Xiangyu Liu Lupeng Han tingting yan Yuejin Li Dengsong Zhang School of Environmental and Chemical Engineering International Joint Laboratory of Catalytic ChemistryCollege of SciencesShanghai UniversityShanghai 200444China BASF Environmental Catalyst and Metal Solutions IselinNJ 08830United States

Development of hydrothermally stable,low-temperature catalysts for controlling nitrogen oxides emissions from mobile sources remains an urgent *** have prepared a metal oxide-zeolite composite catalyst by depositing Mn active species on a mixture support of CeO_(2)/Al_(2)O_(3) and *** composite catalyst is hydrothermally stable and shows improved low-temperature SCR activity and significantly reduced N_(2)O formation than the corresponding metal oxide *** with a Cu-CHA catalyst,the composite catalyst has a faster response to NH_(3) injection and less NH_(3) *** characterization results reveal that such an oxide-zeolite composite catalyst contains more acidic sites and Mn^(3+)species as a result of oxide-zeolite interaction,and this interaction leads to the generation of more NH_(4)^(+)species bound to the Br?nsted acid sites and more reactive NOxspecies absorbed on the Mn ***,we report our mechanistic understanding of the oxide-zeolite composite catalyst and its molecular pathway for improving the low-temperature activity and N_(2) selectivity for NH_(3)-SCR ***,this work may provide an alternative methodology for low-temperature NO_(x) control from diesel vehicles.

关键词： Selective catalytic reduction Mn-based catalysts Hydrothermal stability N_(2) selectivity

Catalytic upgrading biomass-derived ethanol and acetic acid into C4 chemicals

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Science China Chemistry 2024年

作者： tingting yan Mengting Zhang Runzhi Yuan Weili Dai College of Science Civil Aviation University of China School of Materials Science and Engineering & National Institute for Advanced Materials Nankai University

Synthesis of value-added chemicals from biomass is an essential strategy to mitigate the global dependency on fossil resources and achieve the aim of carbon neutrality. Thereinto, ethanol and acetic acid are crucial biomass-derived platform ***, catalytic upgrading ethanol and acetic acid into C4 energy-intensive fuels and chemicals via the elongation of carbon backbone has received widespread attention. The primary focus of this review is to systematically describe the recent breakthrough in the conversion of ethanol or acetic acid to C4 chemicals including 1,3-butadiene, n-butenes, isobutene or *** attentions will be given to heterogeneous catalyst design strategies, reaction parameters on the catalytic performance along with the relevant mechanism investigations, as well as their future challenges and opportunities. The present review will provide the detailed insights into the synthesis of C4 chemicals from biomass-derived ethanol and acetic acid and shed a light on the development of highly efficient catalysts.

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Deactivation mechanism of acetone to isobutene conversion over Y/Beta catalyst

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Chinese Journal of Catalysis 2024年第9期64卷 133-142页

作者： Chang Wang tingting yan Weili Dai School of Materials Science and Engineering Nankai UniversityTianjin 300350China College of Science Civil Aviation University of ChinaTianjin 300300China

The conversion of acetone derived from biomass to isobutene has attracted extensive *** comparison with Brønsted acidic catalyst,Lewis acidic catalyst could exhibit a better catalytic performance with a higher isobutene ***,the catalyst stability remains a key problem for the long-running acetone conversion and the reasons for catalyst deactivation are poorly understood up to ***,the deactivation mechanism of Lewis acidic Y/Beta catalyst during the acetone to isobutene conversion was investigated by various characterization techniques,including acetone-temperature-programmed surface reaction,gas chromatography-mass spectrometry,in situ ultraviolet-visible,and 13C cross polarization magic angle spinning nuclear magnetic resonance spectroscopy.A successive aldol condensation and cyclization were observed as the main side-reactions during the acetone conversion at Lewis acidic Y *** comparison with the low reaction temperature,a rapid formation and accumulation of the larger cyclic unsaturated aldehydes/ketones and aromatics could be observed,and which could strongly adsorb on the Lewis acidic sites,and thus cause the catalyst deactivation *** a simple calcination,the coke deposits could be easily removed and the catalytic activity could be well restored.

关键词： Deactivation mechanism Acetone to isobutene Lewis acid sites Y/Beta Spectroscopy

The COVID-19 Vaccines Evaluation Program:Implementation,Management,and Experiences,2021-2023

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China CDC weekly 2024年第26期6卷 642-648页

作者： tingting yan Hui Zheng Mingshuang Li Chao Ma Xuanyi Wang Xiaoqi Wang Zhenjun Li Yuansheng Chen Wenshang Hu Lance Rodewald Zhijie An Zundong Yin Zijian Feng National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases(NITFID).National Immunization Program Chinese Center for Disease Control and PreventionBeijingChina Institutes of Biomedical Sciences Fudan UniversityShanghaiChina Office of International Cooperation Chinese Center for Disease Control and PreventionBeijingChina Office of Science and Technology Chinese Center for Disease Control and PreventionBeijingChina Office of Finance Chinese Center for Disease Control and PreventionBeijingChina Chinese Preventive Medicine Association BeijingChina

In 2021,China’s domestically produced coronavirus disease 2019(COVID-19)vaccines received approval from regulatory bodies and were administered *** to a low number of infections within China during that period,it became imperative to evaluate the vaccines’real-world effectiveness through international *** facilitate this,China CDC launched the COVID-19 Vaccines Evaluation Program(COVEP).This program formed research collaboration agreements with health institutes across five World Health Organization regions,addressing key questions about vaccine performance through ten cooperative *** findings from COVEP projects reinforced confidence,both domestically and globally,in the effectiveness of the vaccines produced in ***,the outcomes observed internationally were frequently mirrored by later studies conducted within *** thus pioneered a novel approach for fostering cross-national research collaborations,addressing significant public health issues and exemplifying a framework for international *** approach is in line with the strategic objectives and other development efforts of China CDC’s national disease control and prevention initiatives.

关键词： approval COV prevention

赖氨酸维B12合剂联合西沙比利对功能性消化不良腹痛患儿肠道菌群及胃肠功能的影响

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中国微生态学杂志 2024年第2期36卷 201-205页

作者：阎婷婷聂莹杨莹临汾市妇幼保健院儿童医院儿三科山西041000

目的探讨赖氨酸维B12合剂联合西沙比利对功能性消化不良(FD)腹痛患儿肠道菌群及胃肠功能的影响,以期为临床提供参考。方法选取2022年5月至2023年6月于本院收治的90例FD伴腹痛患儿,采用简单随机分组将患儿分为单一组(n=45)和联合组(n=45)... 详细信息

目的探讨赖氨酸维B12合剂联合西沙比利对功能性消化不良(FD)腹痛患儿肠道菌群及胃肠功能的影响,以期为临床提供参考。方法选取2022年5月至2023年6月于本院收治的90例FD伴腹痛患儿,采用简单随机分组将患儿分为单一组(n=45)和联合组(n=45),单一组患儿采用西沙比利治疗,联合组患儿采用赖氨酸维B12合剂联合西沙比利治疗。比较两组患儿的疗效,治疗前后患儿的肠道菌群、胃肠功能和疼痛程度,记录两组患儿治疗期间的不良反应发生情况。结果联合组患儿治疗的有效率为95.56%,单一组为82.22%,差异有统计学意义(χ^(2)=4.050,P0.05)。结论赖氨酸维B12合剂联合西沙比利治疗FD伴腹痛患儿具有较好的临床疗效且无明显不良反应,可以缓解腹痛,改善肠道菌群和胃肠功能。

关键词：赖氨酸维B12合剂西沙比利功能性消化不良腹痛肠道菌群胃肠功能

基于慢性疾病轨迹模式的脑卒中患者康复管理实践与效果评价

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中国护理管理 2024年第6期24卷 856-861页

作者：王琳严婷婷司芬上海市第二康复医院医院感染管理科上海市200441 上海市第二康复医院医院神经康复科上海市200441 上海市第二康复医院医院老年康复科上海市200441

目的:评价基于慢性疾病轨迹模式的脑卒中患者康复管理的应用效果,为我国脑卒中等慢性病的康复管理提供理论参考。方法:便利选择2022年9月1日至2023年10月31日在上海市某康复医院住院治疗的脑卒中患者,在入院前采用随机数字表法分为对照... 详细信息

目的:评价基于慢性疾病轨迹模式的脑卒中患者康复管理的应用效果,为我国脑卒中等慢性病的康复管理提供理论参考。方法:便利选择2022年9月1日至2023年10月31日在上海市某康复医院住院治疗的脑卒中患者,在入院前采用随机数字表法分为对照组(63例)和观察组(65例),分别将对照组和观察组患者分配至医院南楼和北楼的2个病区。对照组采用常规护理康复干预;观察组在常规护理康复干预的基础上,按照慢性疾病轨迹模式进行康复管理。比较2组患者干预前及干预1个月、干预3个月时希望水平、日常生活活动能力及社会参与度的变化。结果:2组患者3个时间点的希望量表评分比较,差异有统计学意义(F_(时间)=389.492,P<0.001;F_(组间)=27.312,P<0.001;F_(交互)=14.059,P<0.001);2组患者3个时间点日常生活活动能力评分比较,差异有统计学意义(F_(时间)=203.751,P<0.001;F_(组间)=5.802,P=0.019,F_(交互)=6.704,P=0.002);2组患者3个时间点的自主参与问卷评分比较,差异有统计学意义(F_(时间)=340.061,P<0.001;F_(组间)=19.525,P<0.001;F_(交互)=7.984,P=0.001)。结论:基于慢性疾病轨迹模式的康复管理能提高脑卒中患者对治疗和生活的希望,同时提高日常生活活动能力,进而提高社会参与度。

关键词：康复疾病管理脑卒中慢性疾病轨迹干预性研究

从若干回鹘文献的缀合看敦煌吐鲁番文献流散的另一路径

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西域研究 2024年第3期 92-104,172页

作者：阿依达尔·米尔卡马力阎婷婷新疆大学中国语言文学学院

国内外各地收藏的回鹘文文献其实皆为流散于世界各地的敦煌吐鲁番文献,其中,北京国家图书馆、敦煌研究院、台北傅斯年图书馆、美国普林斯顿大学东亚图书馆等多地收藏的回鹘文文献可以缀合,呈现出其不同的流散路径。敦煌吐鲁番回鹘文文... 详细信息

国内外各地收藏的回鹘文文献其实皆为流散于世界各地的敦煌吐鲁番文献,其中,北京国家图书馆、敦煌研究院、台北傅斯年图书馆、美国普林斯顿大学东亚图书馆等多地收藏的回鹘文文献可以缀合,呈现出其不同的流散路径。敦煌吐鲁番回鹘文文献的缀合研究不仅可以立体地呈现这些文献的具体内容,亦可对全面认识敦煌吐鲁番文献的流散路径提供材料依据,丰富以往敦煌吐鲁番文献流散情况的认识和结论。

关键词：回鹘文文献文献缀合敦煌吐鲁番文书流散路径

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回火工艺对HT9钢组织和力学性能的影响

金属热处理 2024年第3期49卷 44-50页

作者：谢谱赵吉庆颜廷亭昆明理工大学材料科学与工程学院云南昆明650093 钢铁研究总院有限公司特殊钢研究院北京100081

利用SEM、TEM、相分析和拉伸、冲击试验,研究了不同回火工艺对HT9钢组织演变及力学性能的影响。结果表明,回火工艺通过影响析出相和位错来改变钢的力学性能;HT9钢在回火后的基体组织为板条马氏体,强化相为M_(23)C_(6)碳化物,未观察到其... 详细信息

利用SEM、TEM、相分析和拉伸、冲击试验,研究了不同回火工艺对HT9钢组织演变及力学性能的影响。结果表明,回火工艺通过影响析出相和位错来改变钢的力学性能;HT9钢在回火后的基体组织为板条马氏体,强化相为M_(23)C_(6)碳化物,未观察到其他析出相。随着回火温度升高,基体组织发生回复,位错缠结逐渐规整、减薄为位错网络,形成亚晶,M_(23)C_(6)碳化物发生Ostwald熟化,析出强化和位错强化作用减弱,强度和硬度降低,韧性上升;在770℃回火1~12 h,随着回火时间延长,基体组织回复,M_(23)C_(6)相发生熟化,强度和硬度逐渐降低并伴有一定的时间依赖性。结合力学性能标准,热处理制度为1040℃淬火1 h+770℃回火6 h时,HT9钢的强韧性匹配较好。

关键词： HT9钢 M_(23)C_(6)相组织力学性能热处理工艺位错

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遥感技术在绿色矿山建设和评估中的应用

当代化工研究 2024年第4期 121-123页

作者：闫亭廷宁夏回族自治区遥感调查院宁夏750021

遥感技术作为依据电磁波理论,应用各种传感仪器对远距离目标所辐射和反射的电磁波信息进行收集、处理并最后成像,从而对地面各种地物目标进行探测和识别的一种综合技术,在绿色矿山建设和评估中具有广泛的应用前景。本文着重探讨遥感技... 详细信息

遥感技术作为依据电磁波理论,应用各种传感仪器对远距离目标所辐射和反射的电磁波信息进行收集、处理并最后成像,从而对地面各种地物目标进行探测和识别的一种综合技术,在绿色矿山建设和评估中具有广泛的应用前景。本文着重探讨遥感技术在绿色矿山建设和评估中的有效运用,并深入分析遥感技术的发展趋势,以为绿色矿建建设和评估提供全新方案。研究结果表明,遥感技术在矿区地形地貌监测、环境影响评估、矿山生态系统恢复评估具有较高的应用价值,且在后期发展中,遥感技术会逐步向人工智能和机器学习整合、无人机(UAV)技术广泛应用等趋势前进,旨在绿色矿山建设和评估中发挥出更大的技术价值。

关键词：绿色矿山遥感技术地形地貌