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Low-cost and fluoride-free synthesis of MFI zeolite nanosheets with enhanced stability for benzene alkylation with ethanol

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Journal of Energy Chemistry 2025年第1期100卷 458-468页

作者： Peng Zhu Cun Liu Yiren Yu Guoshu Gao Yumeng zhao Xiongfu Zhang Guodong Liu Guohui Yang State Key Laboratory of Fine Chemicals School of Chemical Engineering Dalian University of Technology State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences

Zeolite nanosheets with a short b-axis thickness are highly desirable in lots of catalytic reactions due to their reduced diffusion resistance. Nevertheless, conventional synthesis methods usually require expensive structure-directing agents(SDAs), pricey raw materials, and eco-unfriendly fluorine-containing additives. Here, we contributed a cost-effective and fluoride-free synthesis method for synthesizing high-quality MFI zeolite nanosheets through a Silicalite-1(Sil-1) seed suspension and urea cooperative strategy, only with inexpensive colloidal silica as the Si source. Our approach was effective for synthesizing both Sil-1 and aluminum-containing ZSM-5 nanosheets. By optimizing key synthesis parameters,including seed aging time, seed quantity, and urea concentration, we achieved precise control over the crystal face aspect ratio and b-axis thickness. We also revealed a non-classical oriented nanosheet growth mechanism, where Sil-1 seeds induced the formation of quasi-ordered precursor particles, and the(010)crystal planes of these particles facilitated urea adsorption, thereby promoting c-axis-oriented *** obtained ZSM-5 nanosheets exhibited exceptional catalytic performance in the benzene alkylation with ethanol, maintaining stability for over 500 h, which is 5 times longer than traditional ZSM-5 catalysts. Furthermore, large-scale production of ZSM-5 nanosheets was successfully carried out in a 3 L highpressure autoclave, yielding samples consistent with those from laboratory-scale synthesis. This work marks a significant step forward in the sustainable and efficient production of MFI nanosheets using inexpensive and environmentally friendly raw materials, offering the broad applicability in catalysis.

关键词： Aspect ratio

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Effect of pouring time on microstructure and mechanical properties of centrifugal cast Ti-46Al alloy tubes

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China Foundry 2025年

作者： Gang Huang Qian Dang Cong-cong Su Jing zhao Chi Zhang Guo-huai Liu zhao-dong Wang The State Key Laboratory of Rolling and Automation Northeastern University School of Materials Science and Engineering Shenyang University of Technology

The grain size of TiAl alloy castings prepared by traditional casting process is coarse, thus showing poor mechanical properties. In this study, a new type of high performance Ti-46Al alloy tube prepared by vacuum centrifugal casting technology was introduced. This research comprehensively examined the influence of pouring time on the microstructure and mechanical performance of the castings, employing both experimental approaches and ProCast simulation methodologies. The findings indicate that prolonging the pouring time facilitates a microstructural evolution from coarse columnar grains to refined equiaxed grains. Under the condition of pouring temperature of 1,600 °C, rotation speed of 800 r·min-1and pouring time of 6 s, the tensile strength of Ti-46Al alloy at room temperature reaches 650 MPa, and the tensile strength at 800 °C reaches 705 MPa, which is significantly higher than that of traditional as-cast Ti-Al alloy.

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Synthesis of Hydroxystilbene Derivatives and their Antioxidant Activity by DPPH Method

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Chemical Research in Chinese Universities 2006年第6期22卷 742-746页

作者： LI Yue-qing SONG Qi-ling CHEN ping-ping zhao Wei-jie WANG shi-sheng State Key Laboratory of Fine Chemicals Dalian University of Technology Dalian 116012 P. R. China

Five hydroxystilbene derivatives were synthesized and their structures were determined using high-resolution mass spectrometry, ^1H NMB, and IR. In this study, the antioxidant activities of eight hydroxystilbenes （five synthesized hydroxystilbene derivatives and three other compounds） were evaluated with the free radiced scavenging model 1,1-diphenyl-2-picrylhydraxyl. It was observed that there exists a very significant linear rehtionship between the reciprocal of the EC50 value of each of the compounds and the maximum wavelength of the ultraviolet absorption peaks, It is believed that this result will be helpful for the further synthesis of such antioxidants.

关键词： Polyhydroxystilbene Antioxidant activity 1,1-Diphenyl-2-picrylhydrazyl (DPPH)

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A Unified Shared-Private Network with Denoising for Dialogue State Tracking

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Journal of Computer Science & Technology 2021年第6期36卷 1407-1419页

作者： Qing-Bin Liu shi-Zhu He Kang Liu Sheng-ping Liu Jun zhao National Laboratory of Pattern Recognition Institute of AutomationChinese Academy of SciencesBeijing 100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China Beijing Unisound Information Technology Co. LtdBeijing 100096China

Dialogue state tracking(DST)leverages dialogue information to predict dialogues states which are generally represented as slot-value ***,previous work usually has limitations to efficiently predict values due to the lack of a powerful strategy for generating values from both the dialogue history and the predefined *** predicting values from the predefined value set,previous discriminative DST methods are difficult to handle unknown *** generative DST methods determine values based on mentions in the dialogue history,which makes it difficult for them to handle uncovered and non-pointable ***,existing generative DST methods usually ignore the unlabeled instances and suffer from the label noise problem,which limits the generation of mentions and eventually hurts *** this paper,we propose a unified shared-private network(USPN)to generate values from both the dialogue history and the predefined values through a unified ***,USPN uses an encoder to construct a complete generative space for each slot and to discern shared information between slots through a shared-private ***,our model predicts values from the generative space through a shared-private *** further utilize reinforcement learning to alleviate the label noise problem by learning indirect supervision from semantic relations between conversational words and predefined slot-value *** results on three public datasets show the effectiveness of USPN by outperforming state-of-the-art baselines in both supervised and unsupervised DST tasks.

关键词： dialogue state tracking unified strategy shared-private network reinforcement learning

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Enhanced subacute ischemic stroke treatment via multistage drug delivery system design for combination therapy

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Science China Chemistry 2025年

作者： Xihan Xu Juan-Juan Li Jiamin Li Hui-Yan Zhang Yilin Qi Bing-Sen shi Tianqi Li Shan-Shan Su Weitao zhao Chang Chen Zhongying Gong Huiyu Liu Ke-Rang Wang Dong-Sheng Guo Xue Xue State Key Laboratory of Medicinal Chemical Biology College of Pharmacy Nankai University College of Chemistry State Key Laboratory of Elemento-Organic Chemistry Key Laboratory of Functional Polymer Materials (Ministry of Education) Frontiers Science Center for New Organic Matter Collaborative Innovation Center of Chemical Science and EngineeringNankai University College of Chemistry and Materials Science State Key Laboratory of New Pharmaceutical Preparations and Excipients Key Laboratory of Medicinal Chemistry and Molecular Diagnosis (Ministry of Education) Key Laboratory of Chemical Biology of Hebei Province Hebei Research Center of the Basic Discipline of Synthetic Chemistry Hebei University Department of Neurology Tianjin First Central Hospital School of Medicine Nankai University Beijing Advanced Innovation Center for Soft Matter Science and Engineering State Key Laboratory of Organic-Inorganic Composites Beijing Laboratory of Biomedical Materials Bionanomaterials & Translational Engineering Laboratory Beijing Key Laboratory of BioprocessBeijing University of Chemical Technology

The management of acute ischemic stroke remains challenging due to its abrupt onset and the narrow treatment window,resulting in high rates of disability and *** therapy for neuroprotection and neurorepair strategies provided new hopes for subacute stroke *** we designed a multistage nanodelivery system that matches the unique microenvironment of the subacute phase of stroke,which utilizes calixarene as a building block to effectively load the neuroprotective drug *** calixarene is designed with glycosidic linkages targeting the glucose transporter 1 (GLUT1)on the blood-brain barrier (BBB) and azo bonds that are responsive to hypoxic ***,the decomposed calixarene molecules themselves possess intrinsic bio-activation to modulate inflammatory responses,achieving a multistage therapeutic approach that transitions from targeting to release and finally to *** approach combines anti-inflammation and neuroprotection,providing a multi-level treatment *** system was validated in a rat model of permanent middle cerebral artery occlusion (pMCAO),demonstrating that intravenous administration of the nanodelivery system repairs brain damage and improves motor function 24 h post-pMCAO *** work offers a precise and integrative strategy for stroke patients missing the acute therapy window to improve functional recovery and enhance the effect of comprehensive treatment.

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Artificial Management Improves Soil Moisture, C, N and P in an Alpine Sandy Meadow of Western China

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Pedosphere 2011年第3期21卷 407-412页

作者： WU Gao-Lin LI Wei zhao Ling-ping shi Zhi-Hua State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F University Yangling712100 (China) Institute of Soil and Water Conservation of Chinese Academy of Sciences and Ministry of Water Resource Yangling712100 (China) Key Laboratory of Arid and Grassland Ecology of the Ministry of Education Lanzhou University Lanzhou 730000 (China)

Regeneration of degraded grassland ecosystems is a significant issue in restoration ecology globally. To understand the effects of artificial management measures on alpine meadows, we surveyed topsoil properties including moisture, organic carbon (SOC), nitrogen (N), and phosphorus (P) contents five years after fencing and fencing + reseeding management practices in a sandy meadow in the eastern Qinghai-Tibetan Plateau, northwestern China. Both the fencing and fencing + reseeding management practices significantly increased soil moisture storage, SOC, total N, available N, total P, and available P, as compared to the unmanaged control. Fencing plus reseeding was more effective than fencing alone for improving soil C, N, and P contents. These suggested that rehabilitation by reseeding and fencing generally had favorable effects on the soil properties in degraded sandy alpine meadows, and was an effective approach for restoration of degraded meadow ecosystems of the Qinghai-Tibetan Plateau.

关键词： degraded ecosystem fencing reseeding restoration ecology soil properties

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Phylogenetic Analysis and Expression Patterns of the MAPK Gene Family in Wheat (Triticum aestivum L.)

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Journal of Integrative Agriculture 2012年第8期11卷 1227-1235页

作者： LIAN Wei-wei TANG Yi-miao GAO shi-qing ZHANG zhao zhao Xin zhao Chang-ping Beijing Engineering and Technique Research Center of Hybrid Wheat Beijing Academy of Agricultural and Forestry Sciences Beijing 100097 P.R.China College of Life Science Capital Normal University Beijing 100048 P.R. China

Mitogen activated protein kinases （MAPK） cascades based on protein phosphorylation play an important role in plant growth and development. In this study, we have identified 15 putative members of the wheat MAPK gene （TaMPK） family through an in silico search of wheat expressed sequence tags （EST） databases based on the presence of amino acid sequence of Arabidopsis and rice MAPKs. Phylogenetic analyses of MAPKs from wheat, rice and Arabidopsis genomes have classified them into seven subgroups （A, B, C, D, E, F, and G）. Using the available EST information as a source of expression data, the MAPK family genes from Triticum aestivum were detected in diverse tissues. Further expression analysis of the MAPKs in NCBI EST database revealed that their transcripts were most abundant in callus （20%）, followed by leaf （12%） and inflorescence （12%）. Most MAPK family genes showed some tissue specificity.

关键词： wheat MAPK EST phylogenetic analysis profile

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结直肠癌进展与抑制的十字路口:间充质干细胞治疗干预效果及难题

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中国组织工程研究 2025年第23期29卷 5022-5030页

作者：郭昭庄浩岩史学文山东中医药大学第一临床医学院山东省济南市250000 山东中医药大学附属医院肛肠科山东省济南市250000

背景:结直肠癌早期的治疗方法包括内镜和手术切除,但是术后并发症多,晚期多采用化疗方法,然而化疗会引起胃肠功能紊乱、骨髓抑制、肝肾功能损伤等不良反应,导致大多数患者不主动、不配合治疗。目的:综述间充质干细胞治疗结直肠癌的作用... 详细信息

背景:结直肠癌早期的治疗方法包括内镜和手术切除,但是术后并发症多,晚期多采用化疗方法,然而化疗会引起胃肠功能紊乱、骨髓抑制、肝肾功能损伤等不良反应,导致大多数患者不主动、不配合治疗。目的:综述间充质干细胞治疗结直肠癌的作用机制、最新治疗进展及目前存在的问题,为将来临床应用提供依据。方法:计算机检索Pub Med数据库、中国知网、万方数据库收录的相关文献。英文检索词为“mesenchymal stem cells,colorectal cancer,cancer stem cell,tumor microenvironment”,中文检索词为“间充质干细胞,结直肠癌,癌症干细胞,肿瘤微环境”,最终纳入119篇文献进行分析。结果与结论:(1)间充质干细胞对于结直肠癌具有促进和抑制的双面作用;(2)间充质干细胞的肿瘤归巢特性使其能够准确迁移到肿瘤位置并释放药物,基于这一特性,增加了治疗结直肠癌的安全性和有效性;(3)间充质干细胞衍生的外泌体作为良好的药物载体,在结直肠癌靶向治疗中显示出良好的应用前景;(4)使用病毒载体、非病毒载体或其他转染工具将具有成熟抗肿瘤作用的药物加载到间充质干细胞中,共同治疗结直肠癌;(5)间充质干细胞与化疗药物联合使用可以提高化疗药物疗效并降低化疗药物不良反应;(6)间充质干细胞促进结直肠癌的发展机制主要与结直肠癌细胞中的信号转导、趋化因子的表达状态及间充质干细胞向癌症相关成纤维细胞转化有关;(7)间充质干细胞可能具有驱动癌症干细胞的特性,促进肿瘤起始并提高肿瘤侵袭性;(8)间充质干细胞治疗结直肠癌还存在着不可避免的问题:缺乏标准化治疗方案及疗效评价方法、治疗成本高昂、间充质干细胞的保存与运输问题、间充质干细胞与化疗药物共同使用的比例等。

关键词：结直肠癌间充质干细胞癌症干细胞肿瘤微环境化疗外泌体

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A method for support stiffness failure identification in a steel spring floating slab track of urban railway: a case study in China

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第3期25卷 206-222页

作者： Junyuan ZHENG Caiyou zhao Duojia shi ping WANG Jian WANG Bolong JIANG Xi SHENG Key Laboratoryof High-speed Railway Engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 60031China School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China 01 DYNA(Qingdao)Test&Data Co. Ltd.Qingdao 266000China Rail Transit Digital Construction and Measurement Technology National Engineering Research Center China Railway Design CorporationTianjin300308China Institute of Urban Smart Transportation&Safety Maintenance Shenzhen UniversityShenzhen 518060China

The extensive use of steel spring floating slab tracks has effectively addressed the challenge of alleviating the environmental vibrations induced by urban rail transit ***,under the combined action of train dynamic loads and complex environmental factors,problems,such as the fracture of steel spring vibration isolators and suspension vibrations induced by the uneven settlement of the base,often *** failure of isolator support stiffness is often hidden in its early stages and is challenging to identify by conventional detection *** the same time,it will aggravate the wheel-rail interaction,accelerate the deterioration of track structure,and even affect the driving *** study first establishes a detailed coupled train-floating slab track-foundation analytical *** the influence of the vibration isolator support stiffness failure on the dynamic indices of the floating slab track system response is analyzed.A set of defect identification methods that can detect the number of failed steel springs,severity of damage,and their location is ***,an intelligent monitoring system for support stiffness of floating slab track is built by combining the density-based spatial clustering of applications with noise algorithm and statistical data analysis and is applied to a rail line in southern *** a three-year monitoring campaign,a suspension failure and a fracture of a steel spring were each successfully detected and detailed failure information was *** investigation results were consistent with the damage identification *** repair,the track structure dynamic response returned to the average pre-damage level and further deterioration had been *** proposed damage identification methods and monitoring system provide an approach for intelligent identification of track structure support stiffness failures.

关键词： Floating slab track Support stiffness Detailed analytical model Failure identification Monitoring system

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Nano-scale compositional oscillation and phase intergrowth in Cu_(2)S_(0.5)Se_(0.5) and their role in thermal transport

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Journal of Materials Science & Technology 2021年第20期79卷 222-229页

作者： Yuyu Wei ping Lu Chenxi Zhu Kunpeng zhao Xun shi Lidong Chen Fangfang Xu State Key Laboratory of High Performance Ceramics and Superfine Microstructures Shanghai Institute of CeramicsChinese Academy of Sciences(CAS)Shanghai 200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Solid solution alloying is a promising strategy to establish high performance *** alloying different elements,phase structures and phase compositions may vary accompanied by appearance of variety of interesting microstructures including mass fluctuation,lattice strain,nano-scale defects and spinodal decomposition,all of which may greatly influence the electrical and specifically the thermal transport of the *** the present study,atomic structures of Cu_(2)S_(0.5)Se_(0.5) solid solution have been examined by using atom-resolved electron microscopy in order to investigate the structure-correlated physical insights for the abnormal thermal transport in this solid *** the exceptional intergrowth nanostructures were *** solid solution consists of two high symmetrical phases,*** hexagonal and cubic phase,which alternately intergrow to form highly oriented ultra-thin lamellae of nano or even,unit cell *** compositional oscillation in Se/S atomic ratio during alloying is responsible for the phase stability and intergrowth *** unique binary phase intergrowth nanostructures make great contribution to the ultra-low lattice thermal conductivity comparable to glass and extremely short phonon mean free path of only 1.04Å,peculiar continuous hexagonal-to-cubic structural transformation without a critical transition temperature and its corresponding abnormal changes of thermal characters with *** present study further evokes the unlimited possibilities and potentials for tailoring nanostructures by alloying for improved thermoelectric performance.

关键词： Thermoelectric Solid solution Intergrowth nanostructures Compositional oscillation Structural transformation Thermal transport

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