检索结果-南通市图书馆

Journal of Iron and Steel Research International 2024年第3期31卷 767-777页

作者： Hong-bin Dai Jian miao Jia-xin Lin School of Materials Science and Engineering Harbin University of Science and TechnologyHarbin 150040HeilongjiangChina

The welding arc,as a carrier for the conversion of electrical energy to thermal energy,has a direct impact on the quality of welding by its properties and *** the tungsten inert gas(TIG)welding process under the condition of Ar-He alternating gas supply,the arc is alternately converted between Ar arc and He arc with an alternating gas supply cycle,which has obvious arc change *** FLUENT software was used to numerically simulate the characteristics of the TIG arc under the condition of alternating gas supply,and the arc temperature field,arc pressure,electric potential and current density distribution under the condition of alternating gas supply were *** with the real-time data of arc pressure measured by the water-cooled copper plate with holes,it is proved that the TIG arc has obvious dynamic characteristics under the condition of Ar-He alternating gas *** unique dynamic TIG arc acts on the 5A06 aluminum alloy weld,causing the molten pool to stir,resulting in uniform microstructure and grain refinement at the weld,and thereby improving the mechanical properties of the welded joint.

关键词： Alternating gas supply Grain refinement Numerical simulation Tungsten argon arc morphology Microstructure Mechanical property

Synergistic asymmetric diarylation of tethered alkenes via C–H functionalization of simple(hetero)arenes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第8期67卷 2710-2718页

作者： Jian Yao Can Zhao lili Shao Xiaohong Huo Xiaoming Wang Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Frontiers Science Center for Transformative MoleculesSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Organometallic Chemistry and Shanghai Hongkong Joint Laboratory in Chemical Synthesis Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China

By virtue of the atom-and step-economy, utilization of simple arenes as a supplant of pre-prepared aryl metal species or aryl halides for the synthesis of arylated chiral molecules has attracted great attention from the synthetic community. While transition-metal-catalyzed enantioselective diarylation of tethered alkenes has been employed to prepare important chiral cyclic compounds, the direct use of simple arenes as aryl precursors is still underdeveloped, probably due to the difficulties in the effective control of the reactivity, site-selectivity and/or enantioselectivity. Herein we report an asymmetric Pd/Ag dual metal catalytic system for the non-directed, site-and enantioselective domino Heck/intermolecular C–H functionalization of *** studies showed that Pd and Ag act in cooperation in the catalysis and the chiral bisphosphine ligand plays a bifunctional role, i.e., assisting the silver species in the cleavage of the aryl C–H bond, while inducing the enantioselectivity on direct complexation with palladium. This method provides an efficient approach to the corresponding chiral oxindoles with good enantiomeric excesses from a broad scope of arenes, including fluoroarenes, heteroarenes and several complex products derived from medicines or natural products.

关键词： asymmetric Pd/Ag dual metal catalytic system simple arenes C–H functionalization bifunctional role chiral oxindoles

International standard of Traditional Chinese Medicine techniques: the operating specification for Traditional Chinese Medicine enema(2022)

在线全文

学校读者我要写书评

暂无评论

Journal of Traditional Chinese Medicine 2024年第5期44卷 1035-1043页

作者： YU miao PEI Xiaohua Department of General surgery Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University Department of Chest and Breast Surgery Beijing University of Chinese Medicine Xiamen Hospital

Chinese Medicine Enema is one of the external therapies in Traditional Chinese Medicine(TCM), which has been widely used clinically. The "International Standard of Traditional Chinese Medicine Techniques: The Operating Specifications for Chinese Medicine Enema is drawn up by the Beijing Hospital of Traditional Chinese Medicine affiliated to Capital Medical University and Beijing University of Chinese Medicine Xiamen Hospital in collaboration with domestic TCM universities and hospitals. The specification includes definition, operating process, points for attention and contraindications. It is targeted to provide reference for TCM providers at home and abroad with TCM background in clinical decision-making.

关键词： Chinese Medicine Enema international standard operating specifications traditional Chinese medical technology

同方期刊数据库

Origin and evolution of false brinelling and fretting corrosion under rolling conditions

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第4期12卷 618-631页

作者： Xin JIA Lu HUANG miao SUN Wenbin LI National Institute of Metrology Beijing 100029China Yantai Tiancheng Machinery Co. Ltd.Yantai 264006China

Rolling bearings working in oscillating applications often suffer from false brinelling and fretting corrosion that limit their service *** present,the study of oscillation-induced failures is primarily dominated by a large number of sliding and bench ***,most of the previous work are not able to fully describe the two closely related but different failure *** this study,the origin and evolution of the two failures are thoroughly investigated under strictly controlled oscillating rolling *** results show that failure evolves from false brinelling to fretting corrosion under dry friction conditions regardless of the oscillation *** process is accompanied by a large area peeling and serious oxidation,and the oxygen content increases from 2.50 wt%to 21.22 wt%.Oxidation is a crucial factor in the evolution of false brinelling into fretting ***,the distribution of microwear and oxygen content depend on the oscillation *** lubrication conditions,the friction coefficient(COF)is smaller in the initial stage and led to local slip or transient instability of rolling ***,the size of the wear marks and COF increased and appeared to be larger than those under a dry friction ***,grease can separate the contact surfaces,only surface deformation owing to false brinelling and slight damage at the roughness level *** evolution of false brinelling and fretting corrosion is also closely related to residual *** brinelling often occurrs with residual stress accomulation,meanwhile,the residual stress increases from 120 to 300 *** peeling occurs,residual stress is *** failure pattern transformed from false brinelling to fretting corrosion and is accompanied by *** far,none of investigation is able to show satisfactory evolution of oscillating-induced failures,this study may contribute to more scientific understanding of rolling bearings against long-

关键词： oscillating false brinelling fretting corrosion wear residual stress

Leveraging plant biomechanics in multiscale plant systems for sustainable innovations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2024年第8期17卷 1159-1163页

作者： Jinbo Shen Yansong miao State Key Laboratory of Subtropical Silviculture Zhejiang A&F UniversityHangzhou 311300China institute for Digital Molecular Analytics and Science Nanyang Technological UniversitySingapore 636921Singapore School of Biological Sciences Nanyang Technological UniversitySingapore 637551Singapore

Integration of mechanical properties with the biomolecular network is fundamental in understanding various developmental and resilience signaling in *** mechanical properties of the cell wall-plasma membrane-cytoskeleton continuum and interconnected endomembrane system can regulate plant growth signaling and plant-microbiome interactions that unlock new opportunities for enhancing crop yield and defense,thereby promoting sustainable agriculture and food security.

关键词： aging thereby sustainable

The Lower Cambrian Xiaoerbulake Formation in the Tarim Basin as a potential carbonate source rock

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy Geoscience 2024年第2期5卷 40-52页

作者： miaoqing miao Zhichao Sun Zongan Xue miao miao Kunpeng Jiang Xuefeng Zhang Zhongkai Bai Xiuxiang Lyu Xingui Zhou Yongjin Gao miao Han Youxing Yang Oil and Gas Survey CGSBeijing100083China School of Earth and Space Sciences Peking UniversityBeijing100871China Institute of Energy Peking UniversityBeijing100871China State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China School of GeoSciences China University of Petroleum(Beijing)Beijing102249China

The oil and gas exploration of the Middle and Lower Cambrian in the Tarim Basin reveals widely distributed source rocks with the Yuertusi Formation being recognized as high-quality source rocks that are distributed in a rather small *** Xiaoerbulake Formation that is right under the Yuertusi Formation has also been eyed as potential high-quality source rocks and is studied through analyses focusing on the stratigraphic development,the abundance,type,and maturity of organic matter,and the paleoproductivity of a dark-colored algae dolomite within the *** results show that the dolomite is rich in organic matter of mainly types Ⅰ and Ⅱ *** reached the high mature to over-mature stage,the dolomite was deposited in an anoxic sedimentary environment featuring a high paleoproductivity level and a high organic carbon burial efficiency,quite favorable for the development of high-quality source *** study provides material evidence to the Middle-Lower Cambrian subsalt source rock-reservoir-caprock combination model for the Tarim Basin.

关键词： Source rock Algal dolomite Yuertusi formation Xiaoerbulake formation Tarim basin

腺病毒介导凋亡素诱导人大细胞肺癌NCI-H460细胞凋亡的研究

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

重庆医科大学学报 2015年第2期40卷 280-285页

作者：阮军任春利缪李丽重庆医科大学附属永川医院呼吸内科重庆402160

目的:构建携带VP3基因重组腺病毒载体(p Adxsi-GFP-VP3),探讨凋亡素(Apoptin)在人大细胞肺癌NCI-H460细胞中的表达及诱导凋亡效应。方法:以pc DNA3.1-VP3重组质粒为模板,经酶切将VP3基因连接至穿梭质粒,后转移至p Adxsi载体上,收获p Adx... 详细信息

目的:构建携带VP3基因重组腺病毒载体(p Adxsi-GFP-VP3),探讨凋亡素(Apoptin)在人大细胞肺癌NCI-H460细胞中的表达及诱导凋亡效应。方法:以pc DNA3.1-VP3重组质粒为模板,经酶切将VP3基因连接至穿梭质粒,后转移至p Adxsi载体上,收获p Adxsi-GFP-VP3,经酶切和测序鉴定正确后进行病毒扩增和纯化,最后测定病毒滴度。将p Adxsi-GFP-VP3以最适感染复数转染入人大细胞肺癌NCI-H460细胞,利用RT-PCR(reverse transcription polymerase chain reaction,RT-PCR)和Western blot技术检测Apoptin在细胞中的表达情况;透射电镜(transmission electron microscopy,TEM)下观察细胞的超微结构;MTT法检测细胞的增殖活性;流式细胞仪(flow cytometry,FCM)检测转染后细胞的凋亡率及细胞周期。结果:成功构建重组腺病毒载体p Adxsi-GFP-VP3,经酶切与测序鉴定证实连接正确,病毒滴度可达1.6×109 PFU/ml。RT-PCR显示转染48 h后Apoptin的m RNA表达;Western blot证实转染72 h后Apoptin蛋白获得高表达。TEM观察发现NCI-H460细胞凋亡早期染色质聚集,线粒体固缩,凋亡中晚期出现凋亡小体等超微形态学改变。MTT法检测显示转染后的NCI-H460细胞增殖活性明显降低,呈时间依赖性(F=93.384,P=0.000),与空病毒组和细胞对照组比较,差异有统计学意义(F=18.427,P=0.003)。FCM法检测显示Apoptin能有效地诱导NCI-H460细胞发生凋亡(F=47.307,P=0.000),且凋亡率随时间呈逐渐上升趋势(F=303.237,P=0.000);细胞周期表现为S期细胞比例降低(F=80.240,P=0.000),G2/M期细胞比例增高(F=110.080,P=0.000)。结论:Apoptin可以有效地诱导人大细胞肺癌NCI-H460细胞发生凋亡,这为Apoptin临床应用于人非小细胞肺癌基因治疗的深入研究奠定实验基础。

关键词：凋亡素大细胞肺癌细胞凋亡基因治疗

Energy-Preserving Parareal-RKN Algorithms for Hamiltonian Systems

在线全文

学校读者我要写书评

暂无评论

NUMERICAL MATHEMATICS-THEORY METHODS AND APPLICATIONS 2024年第1期17卷 121-144页

作者： miao, Zhen Wang, Bin Jiang, Yaolin Northwestern Polytech Univ Sch Math & Stat Xian 710072 Peoples R China Xi An Jiao Tong Univ Sch Math & Stat Xian 710049 Peoples R China

In this paper, we formulate and analyse a kind of parareal-RKN algorithms with energy conservation for Hamiltonian systems. The proposed algorithms are constructed by using the ideas of parareal methods, Runge-Kutta-Nystrom (RKN) methods and projection methods. It is shown that the algorithms can exactly preserve the energy of Hamiltonian systems. Moreover, the convergence of the integrators is rigorously analysed. Three numerical experiments are carried out to support the theoretical results presented in this paper and show the numerical behaviour of the derived algorithms.

关键词： Parareal methods Runge-Kutta-Nystro center dot m methods Hamiltonian systems energy conservation WAVE-FORM RELAXATION TIME INTEGRATORS SIMULATION

Recent progress on Sn_(3)O_(4)nanomaterials for photocatalytic applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 231-244页

作者： Xin Yu Congcong Li Jian Zhang lili Zhao Jinbo Pang Longhua Ding Institute for Advanced Interdisciplinary Research(iAIR) School of Chemistry and Chemical EngineeringUniversity of JinanJinan 250022China School of Sino-German Engineering Shanghai Technical Institute of Electronics and InformationShanghai 201411China Division of Systems and Synthetic Biology Department of Life SciencesChalmers University of Technology41296 GöteborgSweden

Tin(IV)oxide(Sn_(3)O_(4))is layered tin and exhibits mixed valence *** has emerged as a highly promising visible-light pho-tocatalyst,attracting considerable *** comprehensive review is aimed at providing a detailed overview of the latest advance-ments in research,applications,advantages,and challenges associated with Sn_(3)O_(4)photocatalytic *** fundamental con-cepts and principles of Sn_(3)O_(4)are ***_(3)O_(4)possesses a unique crystal structure and optoelectronic properties that allow it to ab-sorb visible light efficiently and generate photoexcited charge carriers that drive photocatalytic ***,strategies for the control and improved performance of Sn_(3)O_(4)photocatalytic nanomaterials are *** control,ion doping,and hetero-structure construction are widely employed in the optimization of the photocatalytic performance of Sn_(3)O_(4)*** effective imple-mentation of these strategies improves the photocatalytic activity and stability of Sn_(3)O_(4)***,the review explores the diverse applications of Sn_(3)O_(4)photocatalytic nanomaterials in various fields,such as photocatalytic degradation,photocatalytic hydro-gen production,photocatalytic reduction of carbon dioxide,solar cells,photocatalytic sterilization,and optoelectronic *** discus-sion focuses on the potential of Sn_(3)O_(4)-based nanomaterials in these applications,highlighting their unique attributes and ***,the review provides an outlook on the future development directions in the field and offers guidance for the exploration and de-velopment of novel and efficient Sn_(3)O_(4)-based *** the identification of emerging research areas and potential avenues for improvement,this review aims to stimulate further advancements in Sn_(3)O_(4)-based photocatalysis and facilitate the translation of this promising technology into practical applications.

关键词： photocatalysis Sn_(3)O_(4)nanomaterials building heterostructures antibacterial therapy water splitting

The importance of data assimilation components for initial conditions and subsequent error growth

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第1期67卷 105-116页

作者： Zhongrui WANG Haohao SUN lili LEI Zhe-Min TAN Yi ZHANG Key Laboratory of Mesoscale Severe Weather Ministry of Educationand School of Atmospheric SciencesNanjing UniversityNanjing 210023China Frontiers Science Center for Critical Earth Material Cycling Nanjing UniversityNanjing 210023China

Despite a specific data assimilation method,data assimilation(DA)in general can be decomposed into components of the prior information,observation forward operator that is given by the observation type,observation error covariances,and background error *** a classic Lorenz model,the influences of the DA components on the initial conditions(ICs)and subsequent forecasts are systematically investigated,which could provide a theoretical basis for the design of DA for different scales of *** forecast errors undergo three typical stages:a slow growth stage from 0 h to 5 d,a fast growth stage from 5 d to around 15 d with significantly different error growth rates for ensemble and deterministic forecasts,and a saturation stage after 15 *** strategies that provide more accurate ICs can improve the *** assimilation is superior to offline assimilation,and a flow-dependent background error covariance matrix(Pf)provides better analyses than a static background error covariance matrix(B)for instantaneous observations and frequent time-averaged observations;but the opposite is true for infrequent time-averaged observations,since cycling simulation cannot construct informative priors when the model lacks predictive skills and the flow-dependent Pf cannot effectively extract information from low-informative observations as the static *** observations contain more information than time-averaged observations,thus the former is preferred,especially for infrequent observing ***,ensemble forecasts have advantages over deterministic forecasts,and the advantages are enlarged with less informative observations and lower predictive-skill model priors.

关键词： Data assimilation Atmospheric predictability Background error covariances Ensemble forecasts