检索结果-南通市图书馆

Effect of droplet characteristics on liquid-phase distribution in spray zone of internal mixing air-mist nozzle

China Foundry 2024年第2期21卷 185-196页

作者： Wei-li Wu Chang-gui cheng Yang li Shi-fa Wei de-li chen The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081China Technology Center Fushun Special Steel Co.Ltd.Fushun 113001LiaoningChina

In continuous casting production,droplet characteristics are important parameters for evaluating the nozzle atomization quality,and have a significant impact on the secondary cooling effect and the slab *** order to study the behavior of atomized droplets after reaching the slab surface and to optimize the spray cooling effect,the influence of droplet diameter and droplet velocity on the migration behavior of droplets in the secondary cooling zone was analyzed by FLUENT *** show that the droplets in the spray zone and on the slab surface are mainly concentrated in the center,thus,the liquid volume fraction in the center is higher than that of either *** the droplet diameter increases,the region of high liquid volume fraction on the slab surface becomes wider,and the liquid phase distribution in the slab width direction becomes *** increasing the droplet velocity at the nozzle exit has little effect on droplet diffusion in the spray zone,the distribution becomes more uneven due to more liquid reaches the slab surface per unit time.A prediction formula of the maximum water flow rate on the slab surface for specific droplet characteristics was proposed based on dimensionless analysis and validated by simulated data.A nozzle spacing of 210 mm was recommended under the working conditions in this study,which ensures effective coverage of the spray water over the slab surface and enhances the distribution uniformity of water flow rate in the transverse direction.

关键词： continuous casting secondary cooling zone internal mixing air-mist nozzle droplet characteristics liquid phase distribution water flow rate

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

PdZn intermetallic compound stabilized on ZnO/nitrogendecorated carbon hollow spheres for catalytic semihydrogenation of alkynols

引用

Nano Research 2022年第4期15卷 3090-3098页

作者： Chunlin Ye Xujian chen Shasha li Binbin Feng Yanghe Fu Fumin Zhang de-li chen Weidong Zhu Key Laboratory of the Ministry of Education for Advanced Catalysis Materials Institute of Physical ChemistryZhejiang Normal UniversityJinhua 321004China

Enhancing the selectivity of noble metal catalysts through electronic modulation is important for academic research and chemical industrial ***,we report a facile sacrificial template strategy for the synthesis of PdZn intermetallic compound(3-4 nm)highly distributed in ZnO/nitrogen-decorated carbon hollow spheres(PdZn-ZnO/NCHS)to optimize the selectivity of Pd catalysts,which involves carbonization of a core-shell structured polystyrene(PS)@ZIF-8 precursor in an inert atmosphere,impregnation Pd precursor,and subsequent H2 reduction *** to the unique structural and compositional features,the developed PdZn-ZnO/NCHS delivers an excellent catalytic performance for the semihydrogenation of 2-methyl-3-butyn-2-ol(MBY)to 2-methyl-3-buten-2-ol(MBE)with high activity(>99%),high selectivity(96%),and good recyclability,outperforming the analog Pd on ZnO(Pd/ZnO)as well as the supported Pd nanoparticles(Pd/C and Pd/NC).density functional theory(DFT)calculations reveal that the presence of Znδ+species in PdZn-ZnO/NCHS alters the adsorption modes of reactant and product,leading to a decrease of the adsorption strength and an enhancement of the energy barrier for overhydrogenation,which results in a kinetic favor for the selective transformation of MBY to *** addition,PdZn-ZnO/NCHS was also very effective for the partial hydrogenation of dehydrolinalool to hydrolinalool.

关键词： PdZn intermetallic compound semihydrogenation of alkynol MOF-derived N-decorated carbon hollow sphere density functional theory(DFT)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Selective separation of copper by membrane-electro-winning and its application in etchant recycling

引用

Journal of Central South University of Technology 2005年第z1期12卷 94-97页

作者： li de-liang chen Ren-hua Institute of Environmental Engineering Central South Forest University Changsha 410004 China Changsha Luyi Environmental Technology Co Ltd Changsha 410008 China

A close-looped process based on the membrane separation and electrolysis is proposed to regenerate the copper etchant in-situ, recover copper on-site and reuse it. It is characterized by selective separation of copper from the spent etchant, which is accomplished by the ion exchange membrane-electrowinning, and at the same time the other components useful for etching are reclaimed. The experiments show that at least 90 % of electricity efficiency for copper removal can be maintained and the optimum condition for membrane-electrowinning is: cell voltage 2 -2.5 V, operating temperature 40 - 50 ℃ and current density 500 - 1 500 A/m2. The regenerated etchant can be suc cessfully reused to etch copper after adjusting its composition to the normal range, and its recycling property is as good as that of the fresh etchant after 50 times of use-disposal-regeneration cycles.

关键词： copper etchant membrane-electrowinning(M-E) recycle selective separation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Mechanism and prediction of failure of diamond films deposited on various substrates by HFCVD

引用

中国有色金属学会会刊：英文版 2004年第z1期14卷 229-233页

作者： ZHOU ling-ping SUN Xin-yuan li Shao-lu li de-yi chen Xiao-hua College of Material Science and Engineering Hunan University Changsha 410082 China College of Material Science and Engineering Hunan University Changsha 410082 China College of Material Science and Engineering Hunan University Changsha 410082 China College of Material Science and Engineering Hunan University Changsha 410082 China College of Material Science and Engineering Hunan University Changsha 410082 China

Diamond films were deposited on the WC-Co cemented carbide and Si3N4 ceramic cutting tool substrates by hot-filament-assisted chemical vapour deposition. The adherence property of diamond films was estimated using the critical load (Pcr) in the indentation test. The adhesive strength of diamond films is related to the intermediate layer between the film and the substrate. Poor adhesion of diamond films to polished cemented carbide substrate is owing to the formation of graphite phase in the interface. The adhesion of diamond films deposited on acid etched cemented carbide substrate is improved, and the peeling-off of the films often happens in the loosen layer of WC particles where the cobalt element is nearly removed. The diamond films' adhesion to cemented carbide substrate whose surface layer is decarbonizated is strengthened dramatically because WC phase forms by reaction between the deposited carbon and tungsten in the surface layer of substrates during the deposition of diamond, which results in chemical combination in the film-substrate interface. The adhesion of diamond films to silicon nitride substrate is the firmest due to the formation of chemical combination of the SiC intermediate layer in the interfaces. In the piston-turning application, the diamond-coated Si3N4 ceramic and the cemented carbide cutting tools usually fail in the form of collapsing of edge and cracking or flaking respectively. They have no built-up edge(BUE) as long as coating is *** it wears through, BUE develops and the cutting force on it increases 1 - 3 times than that prior to failure. This can predict the failure of diamond-coated cutting tools.

关键词： diamond film cutting tool adhesion failure prediction cemented carbide

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Construction of isolated Ni sites on nitrogen-doped hollow carbon spheres with Ni-N_(3) configuration for enhanced reduction of nitroarenes

引用

Nano Research 2022年第7期15卷 6001-6009页

作者： Binbin Feng Rou Guo Qiulan Cai Yaping Song Nan li Yanghe Fu de-li chen Jiangwei Zhang Weidong Zhu Fumin Zhang Key Laboratory of the Ministry of Education for Advanced Catalysis Materials Institute of Physical ChemistryZhejiang Normal UniversityJinhua 321004China Dalian National Laboratory for Clean Energy&State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China

designing and synthesizing high-efficiency non-precious metal-based catalysts having uniform active sites increases the reactivity and selectivity of materials and provides a platform for an in-depth understanding of their catalytic reaction *** this study,we provided an approach for fabricating isolated nickel single-atom sites(Ni SAs)with high loading(4.9 wt.%)stabilized on nitrogen-doped hollow carbon spheres(NHCS)using a core–shell structured Zn/Ni bimetallic zeolitic imidazolate framework(ZIF)composite as the sacrificial *** as-fabricated Ni SAs/NHCS catalyst shows superior activity,selectivity,and recycling durability for the catalytic transfer hydrogenation of nitrobenzene to aniline,thus achieving 100%yield of aniline with a turn-over frequency(TOF)value as high as 29.9 h^(−1) under mild *** TOF value is considerably superior to the supported Ni nanoparticle *** experiments designed show that the hollow structure feature of NHCS facilitates accessible active sites and mass transfer,which thus contributes to the enhancement of the catalytic performance of Ni SAs/*** functional theory calculations show the high chemo-selectivity and activity of the Ni SAs catalyst,arising from the unique role of the single Ni-N3 site on simultaneously activating the H donor(N_(2)H_(4))and substrate,as well as the hydrogenation of the–NOH group as the rate-determining step.

关键词： single-atom catalyst chemo-selective reduction nitro compounds aromatic amines

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

GaP-Based High-Efficiency Elliptical Cylinder Metasurface in Visible light

引用

Chinese Physics Letters 2020年第5期37卷 98-101页

作者： Shuai-Meng Wang Xiao-Hong Sun de-li chen Fan Wu Henan Key Laboratory of Laser and Opto-electric Information Technology School of Information EngineeringZhengzhou UniversityZhengzhou 450052

Compared with the metal antenna metasurface,the dielectric metasurface has better optical characteristics and smaller ohmic loss in the optical band,which makes it *** elliptical cylindrical nanostructured antenna is designed using GaP with excellent transmission characteristics in the visible *** structure has a transmjssion efficiency of up to 0.96 in the visible light *** on the Pancharatnam-Berry(PB)phase control principle,the metasurface structure composed of the antennas is studied,and its abnormal refraction metasurface and focusing meta-lens are *** is a highly ef Rcient sub-wavelength structure,and promises great potential for the applications of circular polarization optics,nanolithography,dense storage and biophotonics.

关键词： visible cylindrical Berry

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Hepatic perivascular epithelioid cell tumor:Clinicopathological analysis of 26 cases with emphasis on disease management and prognosis

引用

World Journal of Gastroenterology 2021年第35期27卷 5967-5977页

作者： Shan Zhang Pan-Pan Yang Yu-chen Huang Hong-Chun chen de-li chen Wen-Tian Yan Ning-Ning Yang Yuan li Nan li Zhen-Zhong Feng department of Pathology The Second People’s Hospital of HefeiHefei 230011Anhui ProvinceChina department of Pathology The Second Affiliated Hospital of Anhui Medical UniversityHefei 230601Anhui ProvinceChina department of Pathology The First Affiliated Hospital of Bengbu Medical CollegeBengbu 233000Anhui ProvinceChina department of Gastrointestinal Surgery The First Affiliated Hospital of Bengbu Medical CollegeBengbu 233000Anhui ProvinceChina department of Pathology The First Affiliated Hospital of University of Science and Technology of ChinaAnhui Provincial HospitalHefei 230001Anhui ProvinceChina

BACKGROUND Perivascular epithelioid cell tumor(PEComa)is an uncommon tumor of mesenchymal *** of PEComa in the liver are extremely *** To analyze the clinicopathological features and treatment of hepatic PEComa and to evaluate the prognosis after different *** Clinical and pathological data of 26 patients with hepatic PEComa were *** cases were analyzed by immunohistochemistry and clinical *** This study included 17 females and 9 males,with a median age of 50 *** were located in the left hepatic lobe in 13 cases,in the right lobe in 11,and in the caudate lobe in *** median tumor diameter was 6.5 *** microscopy revealed that the tumor cells were mainly composed of epithelioid *** cytoplasm contained heterogeneous eosinophilic *** were thick-walled blood vessels,around which tumor cells were radially *** analysis of pigment-derived and myogenic markers in PEComas revealed that 25 cases were HMB45(+),23 were Melan-A(+),and 22 SMA(+).TFE3 and desmin were negative in all *** the fluorescence in situ hybridization samples were negative for TFE3 gene break-apart *** tissues were collected by extended hepatic lobe resection or simple hepatic tumor resection as the main *** follow-up was 62.5 *** of the patients had metastasis or recurrence,and there were no deaths due to the *** Hepatic PEComa highly expresses melanin and smooth muscle markers,and generally exhibits an inert biological *** prognosis after extended hepatic lobe resection and simple hepatic tumor resection is semblable.

关键词： Hepatic tumor Perivascular epithelioid cells PEComa Immunohistochemistry Treatment Prognosis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Arabidopsis Galacturonosyltransferase （GAUT） 13 and GAUT14 Have Redundant Functions in Pollen Tube Growth

引用

Molecular Plant 2013年第4期6卷 1131-1148页

作者： li Wang Wei Wang You-Qun Wang Yang-Yang liu Jing-Xin Wang Xue-Qin Zhang de Ye li-Qun chen State Key Laboratory of Plant Physiology and Biochemistry College of Biological Sciences China Agricultural University Beijing 100193 China

Cell wall biosynthesis is indispensable for pollen tube growth. despite its importance to sexual reproduction, the molecular mechanisms of pollen tube wall biosynthesis remain poorly understood. Here, we report functional characterization of two putative Arabidopsis galacturonosyltransferase genes, GAUT13 and GAUT14, which are essential for pollen tube growth. GAUT13 and GAUT14 encode the proteins that share a high amino acid sequence identity and are located in the Golgi apparatus. The T-DNA insertion mutants, gaut13 and gaut14, did not exhibit any observable defects, but the gaut13 gaut14 double mutants were defective in pollen tube growth; 35.2-37.3% pollen tubes in the heterozygous double mutants were swollen and defective in elongation. The outer layer of the cell wall did not appear distinctly fibrillar in the double mutant pollen tubes. Furthermore, distribution of homogalacturonan labeled with JIM5 and JIM7 in the double mutant pollen tube wall was significantly altered compared to wild-type. Our results suggest that GAUT13 and GAUT14 function redundantly in pollen tube growth, possibly through participation in pectin biosynthesis of the pollen tube wall.

关键词： Arabidopsis cell wall GAUT13 GAUT14 pectin pollen tube.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

基于三周期极小曲面的管道爬行机器人

引用

科学技术与工程 2025年第3期25卷 1133-1141页

作者：梁加龙罗凯李德臣陈飞飞上海交通大学机械与动力工程学院上海200240 中国工程物理研究院计算机应用研究所绵阳621900 中国运载火箭技术研究院北京100076

针对流体运输中的小管径管道检测与维护任务,设计并研制了一种小尺寸软体气动管道爬行机器人。该机器人采用解析隐式三周期极小曲面偏置技术,形成具有厚度的实体结构,并通过调整隐式方程参数实现结构刚度的各向异性。在此基础上,设计了... 详细信息

针对流体运输中的小管径管道检测与维护任务,设计并研制了一种小尺寸软体气动管道爬行机器人。该机器人采用解析隐式三周期极小曲面偏置技术,形成具有厚度的实体结构,并通过调整隐式方程参数实现结构刚度的各向异性。在此基础上,设计了径向和纵向变形驱动器,以满足机器人在管道内的灵活运动需求。为优化机器人性能,提出了一种基于MATLAB、Rhino和ABAQUS的联合参数优化框架,并利用Python脚本实现自动化参数优化流程。通过这一框架,可以有效提高机器人的运动性能和适应性。基于两种变形驱动器,设计了管道爬行机器人的整体结构,并详细阐述了制造方法和运动控制步态。实验结果表明,所设计的管道机器人能够在两种不同姿态以及一定载荷条件下稳定地沿管道运动,验证了联合参数优化框架的可行性。研究成果为后续管道爬行机器人的参数化设计和优化研究提供了有价值的参考,有助于推动软体机器人在小管径管道检测与维护领域的应用发展。

关键词：管道爬行机器人三周期极小曲面驱动器结构参数优化软体机器人

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

CO hydrogenation conversion driven by micro-environments of active sites over iron carbide catalysts

引用

Green Energy & Environment 2025年第2期10卷 367-373页

作者： Nan Song Xingxing li Ebtihal Abograin Wenyao chen Junbo Cao Jing Zhang de chen Xuezhi Duan Xinggui Zhou State Key Laboratory of Chemical Engineering East China University of Science and Technology130 Meilong RoadShanghai200237China department of Chemical Engineering Norwegian University of Science and TechnologyTrondheim7491Norway

Essentially clearing the structure-activity relationship between iron carbide catalysts involving multiple active centers to understand the reaction mechanism of CO hydrogenation conversion process is still a great ***,two main micro-environment factors,namely electronic properties and geometrical effects were found to have an integrated effect on the mechanism of CO hydrogenation conversion,involving active sites on multiple crystal *** Bader charge of the surface Fe atoms on the active sites had a guiding effect on the CO activation pathway,while the spatial configuration of the active sites greatly affected the energy barriers of CO *** the defective surfaces were more conducive to CO activation,the defective sites were not the only sites to dissociate CO,as CO always tended to dissociate in a wider *** synergistic effect of the micro-environment also occurred during the CO conversion *** C atoms on relatively flat configurations were more likely to form methane,while the electronic properties of the active sites could effectively describe the C-C coupling process,as well as distinguish the coupling mechanisms.

关键词： Micro-environment CO hydrogenation conversion Electronic property Local environment Synergistic effect

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：