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Catalyst design and structure control for photocatalytic refineries of cellulosic biomass to fuels and chemicals

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Journal of Energy Chemistry 2024年第7期94卷 102-127页

作者： Lulu sun Nengchao Luo State Key Laboratory of Catalysis Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina

Lignocellulosic biomass is the largest renewable hydrocarbon resource on *** cellulose,one of the major components of lignocellulose,powered by solar energy is a promising way of providing lowcarbon-footprint energy chemicals such as H_(2),HCOOH,CO,and transportation ***-of-the-art biorefineries target the full use of biomass feedstocks as they have a maximum collection radius of 75-100 km,requesting efficient and selective photocatalysts that significantly influence the outcome of photocatalytic ***-performed photocatalysts can harvest a broad solar spectrum and are active in breaking the chemical bonds of cellulose,decreasing the capital investments of ***,photocatalysts should control the selectivity of cellulose conversion,originating target products to level down separation *** separation in photocatalysts and interfacial charge transfer between photocatalysts and cellulose affect the activity and selectivity of cellulose refineries to H2 and carbonaceous *** account for the challenges above,this review summarizes photocatalysts for the refineries of cellulose and downstream platform molecules based on the types of products,with the structure features of different types of photocatalysts discussed in relation to the targets of either improving the activity or product *** addition,this review also sheds light on the methods for designing and regulating photocatalyst structures to facilitate photocatalytic refineries of cellulose and platform molecules,meanwhile summarizing proposed future research challenges and opportunities for designing efficient photocatalysts.

关键词： Photocatalysts Biorefineries Cellulose Fuels Hydrogen

Self-Aligning Multi-Modal Transformer for Oropharyngeal Swab Point Localization

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Tsinghua Science and Technology 2024年第4期29卷 1082-1091页

作者： Tianyu Liu Fuchun sun Department of Computer Science and Technology Tsinghua UniversityBeijing 100083China

The oropharyngeal swabbing is a pre-diagnostic procedure used to test various respiratory diseases, including COVID and Influenza A (H1N1). To improve the testing efficiency of testing, a real-time, accurate, and robust sampling point localization algorithm is needed for robots. However, current solutions rely heavily on visual input, which is not reliable enough for large-scale deployment. The transformer has significantly improved the performance of image-related tasks and challenged the dominance of traditional convolutional neural networks (CNNs) in the image field. Inspired by its success, we propose a novel self-aligning multi-modal transformer (SAMMT) to dynamically attend to different parts of unaligned feature maps, preventing information loss caused by perspective disparity and simplifying overall implementation. Unlike preexisting multi-modal transformers, our attention mechanism works in image space instead of embedding space, rendering the need for the sensor registration process obsolete. To facilitate the multi-modal task, we collected and annotate an oropharynx localization/segmentation dataset by trained medical personnel. This dataset is open-sourced and can be used for future multi-modal research. Our experiments show that our model improves the performance of the localization task by 4.2% compared to the pure visual model, and reduces the pixel-wise error rate of the segmentation task by 16.7% compared to the CNN baseline.

关键词： segmentation localization transformer multi-modal perception robotic perception

全新世北半球中纬度降水变化对不同外强迫响应的模拟研究

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第四纪研究 2020年第6期40卷 1588-1596页

作者：孙炜毅刘健万凌峰宁亮严蜜虚拟地理环境教育部重点实验室/江苏省地理环境演化国家重点实验室培育建设点/江苏省地理信息资源开发与利用协同创新中心南京师范大学地理科学学院江苏南京210023 江苏省大规模复杂系统数值模拟重点实验室南京师范大学数学科学学院江苏南京210023 青岛海洋科学与技术试点国家实验室海洋-气候-同位素模拟开放工作室山东青岛266237 中国科学院地球环境研究所黄土与第四纪地质国家重点实验室陕西西安710061

北半球中纬度(30°~50°N)降水变化一直是当今社会关注的热点。文章基于重建资料、气候系统模式CCSM开展的TraCE-21 ka瞬变试验和地球系统模式CESM完成的NNU-12k瞬变加速气候模拟试验结果,探讨了全新世以来中纬度降水变化趋势及其对外... 详细信息

北半球中纬度(30°~50°N)降水变化一直是当今社会关注的热点。文章基于重建资料、气候系统模式CCSM开展的TraCE-21 ka瞬变试验和地球系统模式CESM完成的NNU-12k瞬变加速气候模拟试验结果,探讨了全新世以来中纬度降水变化趋势及其对外强迫的响应。结果表明:全新世以来重建的中纬度降水呈增加趋势,在距今10~7 ka,TraCE-21 ka全强迫试验模拟出了这一趋势,主要受陆地冰盖衰退、淡水注入和轨道参数(ORB)的共同影响。在7~0 ka,NNU-12k的ORB试验与重建的降水增加趋势一致,但主要集中在海洋地区。两个模式均模拟出了欧亚大陆中纬度地区比北美大陆干燥的趋势特点,并发现是ORB的作用引起的;而温室气体(GHGs)主要对欧亚大陆降水增强有所贡献,但不能抵消ORB的负贡献。然而,模拟的中纬度降水对全新世以来ORB、GHGs的响应存在模式依赖性,这是今后重建-模拟资料对比时需要考虑的重要因素。

关键词：全新世中纬度降水重建-模拟资料对比轨道参数温室气体

NAO在末次冰盛期和全新世对AMOC影响的对比研究

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第四纪研究 2023年第4期43卷 1042-1052页

作者：高杨刘健温琴孙炜毅宁亮严蜜南京师范大学虚拟地理环境教育部重点实验室/江苏省地理环境演化国家重点实验室培育建设点/江苏省地理信息资源开发与利用协同创新中心南京师范大学地理科学学院江苏南京210023 江苏省大规模复杂系统数值模拟重点实验室南京师范大学数学科学学院江苏南京210023 青岛海洋科学与技术试点国家实验室海洋-气候-同位素模拟开放工作室山东青岛266237 中国科学院地球环境研究所黄土与第四纪地质国家重点实验室陕西西安710061

大西洋经向翻转环流(AMOC)的年代际变率对气候变化起着重要的调制作用。在现代气候背景下,北大西洋涛动(NAO)加强能使AMOC增强,但这种关系在更长时间尺度上是否成立尚不清楚。本研究利用TraCE-21ka模拟资料,对比分析末次冰盛期(LGM)和... 详细信息

大西洋经向翻转环流(AMOC)的年代际变率对气候变化起着重要的调制作用。在现代气候背景下,北大西洋涛动(NAO)加强能使AMOC增强,但这种关系在更长时间尺度上是否成立尚不清楚。本研究利用TraCE-21ka模拟资料,对比分析末次冰盛期(LGM)和全新世时期NAO对AMOC影响的异同。结果表明,LGM时期较全新世时期经向温度梯度偏强,NAO位置偏南,这导致NAO与AMOC关系的不同:NAO的增强在LGM时期可以使AMOC增强,而在全新世使AMOC减弱。具体地,在LGM时期NAO的加强使北大西洋副极地气旋性环流增强,其南支导致向北的高盐海水输送增加,从而使北大西洋副极地区域密度升高,AMOC增强。与此同时,NAO正位相还能在中纬度激发异常的Ekman下沉流使AMOC加强。相反,在全新世时期,NAO正位相导致北大西洋副极地地区气旋性环流减弱,这导致中纬度向高纬度输送的高盐度海水减少,AMOC减弱。本研究表明NAO与AMOC的关系在很大程度上取决于不同气候背景下NAO的位置。

关键词：末次冰盛期全新世北大西洋涛动大西洋经向翻转环流

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连二硫酸锰碳化干渣热解回收硫酸钠的研究

工程科学与技术 2020年第1期52卷 168-174页

作者：曲兵康禄华李忆雯严岩孙维义苏仕军四川大学建筑与环境学院

利用软锰矿进行烟气脱硫或湿法冶金技术研究时,因其既可控制大气污染物二氧化硫亦可回收锰资源而备受关注。然而,反应过程会生成影响脱硫尾液中硫酸锰品质的副产物连二硫酸锰(杂质),如何回收或去除该杂质是新技术研发和推广的难题。作... 详细信息

利用软锰矿进行烟气脱硫或湿法冶金技术研究时,因其既可控制大气污染物二氧化硫亦可回收锰资源而备受关注。然而,反应过程会生成影响脱硫尾液中硫酸锰品质的副产物连二硫酸锰(杂质),如何回收或去除该杂质是新技术研发和推广的难题。作者提出了连二硫酸锰先经碳酸氢钠碳化得到连二硫酸钠和碳酸锰,两产物分离后,结合低温热解的方法将连二硫酸钠制备成无水硫酸钠;实验考察了热解制备过程的各产物和控制反应步骤的温度,进而推理出动力学参数和反应机理。热解实验结果表明:255℃是连二硫酸钠热解制备无水硫酸钠的最佳热解反应温度,并且热解反应过程经历脱硫和脱水两大步骤;热解产物的X射线衍射(XRD)和离子色谱(IC)表征结果表明:最终产物为单一相的立方体结构硫酸钠晶体。利用热重示差扫描热分析(TG–DSC)对连二硫酸钠热解过程进行表征,结合Kissinger微分法和Coats–Redfern积分法对热解法脱水和脱硫过程中的活化能进行推算,脱水和脱硫活化能分别在14.75~18.11 kJ/mol和132.61~137.18 kJ/mol范围内。热解尾气测定结果表明:连二硫酸钠热解制备无水硫酸钠时释放出的尾气主要为二氧化硫。因此,经低温热解工艺处理软锰矿脱硫尾液中连二硫酸根的方法是可行的,不仅可以避免液相处理工艺中酸性废水产生的问题,还可以利用热解制备过程中的尾气去除残留的碳化剂(碳酸钠),以达到资源化回收目的。

关键词：连二硫酸锰硫酸钠碳化热解过程回收

Effect of wire mesh casing treatment on axial compressor performance and stability

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Chinese Journal of Aeronautics 2024年第3期37卷 60-76页

作者： Ming ZHANG Jiaming ZHANG Jiahao HU Xu DONG Dakun sun Xiaofeng sun School of Energy and Power Engineering Beihang UniversityBeijing 100191China Beihang Hangzhou Innovation Institute Yuhang Hangzhou 310023China National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing 100191China

In this paper,a kind of Wire Mesh Casing Treatment(WMCT)is proposed to improve the stable operating range of the *** contrast to the traditional circumferential groove,as for WMCT,a layer of wire mesh is laid on the surface of the circumferential *** studies were conducted on the low-speed axial flow compressor,including the groove width,axial location,and mesh *** optimum axial location for WMCT is related to its groove width.A higher wire mesh count results in a smaller compressor stall margin *** simulations were carried out to study the effect of WMCT on the flow structure of the *** wire mesh in the WMCT has a certain flow resistance,which restricts the flow into and out of the *** to the WMCT,the flow parameter in the tip region of the rotor is less sensitive to changes in the operating conditions of the *** WMCT causes the rotor tip blade loading to shift backward,inhibiting the formation of spill forward of the leakage flow,and thus improving the stability of the *** flow resistance on the groove surface is a new degree-of-freedom for the casing treatment designer.

关键词： Axial compressor Wire mesh casing treatment Tip clearance flow Stall margin Blade loading

Persistent Variations in the East Asian Trough from March to April and the Possible Mechanism

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Advances in Atmospheric Sciences 2024年第4期41卷 737-753,I0002-I0004页

作者： Shui YU Jianqi sun Nansen-Zhu International Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The East Asian trough(EAT)profoundly influences the East Asian spring *** this study,the relationship of the EATs among the three spring months is *** analysis shows that the variation in March EAT is closely related to that of April *** empirical orthogonal function(EEOF)analysis also confirms the co-variation of the March and April *** positive/negative EEOF1 features the persistent strengthened/weakened EAT from March to *** investigation indicates that the variations in EEOF1 are related to a dipole sea surface temperature(SST)pattern over the North Atlantic and the SST anomaly over the tropical Indian *** dipole SST pattern over the North Atlantic,with one center east of Newfoundland Island and another east of Bermuda,could trigger a Rossby wave train to influence the EAT in March−*** SST anomaly over the tropical Indian Ocean can change the Walker circulation and influence the atmospheric circulation over the tropical western Pacific,subsequently impacting the southern part of the EAT in March−*** the SST factors,the Northeast Asian snow cover could change the regional thermal conditions and lead to persistent EAT anomalies from March to *** three impact factors are generally independent of each other,jointly explaining large variations in the EAT ***,the signals of the three factors could be traced back to February,consequently providing a potential prediction source for the EAT variation in March and April.

关键词： spring East Asian trough sea surface temperature snow cover

Pretreating and normalizing metabolomics data for statistical analysis

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Genes & Diseases 2024年第3期11卷 188-205页

作者： Jun sun Yinglin Xia Division of Gastroenterology and Hepatology Department of MedicineDepartment of Microbiology/ImmunologyUIC Cancer CenterUniversity of Illinois ChicagoJesse Brown VA Medical Center Chicago(537)ChicagoIL 60612USA Division of Gastroenterology and Hepatology Department of MedicineUniversity of Illinois ChicagoChicagoIL 60612USA

Metabolomics as a research field and a set of techniques is to study the entire small molecules in biological *** is emerging as a powerful tool generally for pre-cision ***,integration of microbiome and metabolome has revealed the mechanism and functionality of microbiome in human health and ***,metabo-lomics data are very ***/pretreating and normalizing procedures on metabolomics data are usually required before statistical *** this review article,we comprehensively review various methods that are used to preprocess and pretreat metabolo-mics data,including MS-based data and NMR-based data preprocessing,dealing with zero and/or missing values and detecting outliers,data normalization,data centering and scaling,data *** discuss the advantages and limitations of each *** choice for a suitable preprocessing method is determined by the biological hypothesis,the characteristics of the data set,and the selected statistical data analysis *** then provide the perspective of their applications in the microbiome and metabolome research.

关键词： Data centering and scaling Data normalization Data transformation Missing values MS-Baseddata preprocessing NMRData preprocessing Outliers Preprocessing/pretreatment

用硫酸铵焙烧—硫酸浸出工艺从低品位锰矿石中回收锰试验研究

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湿法冶金 2019年第2期38卷 92-95页

作者：鄢然孙维义丁桑岚苏仕军四川大学建筑与环境学院

基于硫酸铵高温热解为硫酸氢铵和氨气,以及硫酸氢铵可将矿石中的锰转化为硫酸锰的特性,研究了采用硫酸铵焙烧—硫酸浸出工艺从低品位锰矿石中回收锰,考察了硫酸铵加入量、焙烧温度、焙烧时间、浸出剂硫酸浓度、浸出温度、浸出时间等条... 详细信息

基于硫酸铵高温热解为硫酸氢铵和氨气,以及硫酸氢铵可将矿石中的锰转化为硫酸锰的特性,研究了采用硫酸铵焙烧—硫酸浸出工艺从低品位锰矿石中回收锰,考察了硫酸铵加入量、焙烧温度、焙烧时间、浸出剂硫酸浓度、浸出温度、浸出时间等条件对锰浸出率的影响。结果表明,在硫酸铵与锰物质的量比为15、温度380℃下对矿石焙烧150 min,然后用浓度为0.04 mol/L的硫酸在40℃下浸出50 min,锰浸出率达95.99%,浸出效果较好。

关键词：硫酸铵碳酸锰焙烧浸出