检索结果-南通市图书馆

Microstructure and mechanical properties stability of pre-hardening treatment in Al-Cu alloys for pre-hardening forming process

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 539-551页

作者： liping tang Pengfei Wei Zhili Hu Qiu Pang Hubei Longzhong laboratory Xiangyang 441000China Hubei Key Laboratory of Advanced Technology for Automotive Components School of Automotive EngineeringWuhan University of TechnologyWuhan 430070China Hubei Engineering Research Center for Green&Precision Material Forming Wuhan University of TechnologyWuhan 430070China Key Laboratory of Metallurgical Equipment and Control Technology of Ministry of Education School of Machinery and AutomationWuhan University of Science and TechnologyWuhan 430081China

The stability of the microstructure and mechanical properties of the pre-hardened sheets during the pre-hardening forming(PHF)process directly determines the quality of the formed *** microstructure stability of the pre-hardened sheets was in-vestigated by differential scanning calorimetry(DSC),transmission electron microscopy(TEM),and small angle X-ray scattering(SAXS),while the mechanical properties and formability were analyzed through uniaxial tensile tests and formability *** results in-dicate that the mechanical properties of the pre-hardened alloys exhibited negligible changes after experiencing 1-month natural aging(NA).The deviations of ultimate tensile strength(UTS),yield strength(YS),and sheet formability(Erichsen value)are all less than 2%.Also,after different NA time(from 48 h to 1 month)is applied to alloys before pre-hardening treatment,the pre-hardened alloys possess stable microstructure and mechanical properties as ***,with the extension of NA time before pre-hardening treatment from 48 h to 1 month,the contribution of NA to the pre-hardening treatment is *** a yield strength increment of 20 MPa is achieved,with no loss in *** limited enhancement is mainly attributed to the fact that only a limited number of clusters are transformed into Guinier-Preston(GP)zones at the early stage of pre-hardening treatment,and the formation ofθ''phase inhibits the nucleation and growth of GP zones as the precipitated phase evolves.

关键词： Al-Cu alloy pre-hardened alloy natural aging mechanical properties microstructure

维普期刊数据库

Alleviating limit cycling in training GANs with an optimization technique

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2024年第6期67卷 1287-1316页

作者： Keke Li liping tang Xinmin Yang National Center for Applied Mathematics in Chongqing Chongqing Normal UniversityChongqing401331China School of Mathematical Sciences University of Electronic Science and Technology of ChinaChengdu611731China

In this paper,we undertake further investigation to alleviate the issue of limit cycling behavior in training generative adversarial networks(GANs)through the proposed predictive centripetal acceleration algorithm(PCAA).Specifically,we first derive the upper and lower complexity bounds of PCAA for a general bilinear game,with the last-iterate convergence rate notably improving upon previous ***,we combine PCAA with the adaptive moment estimation algorithm(Adam)to propose PCAA-Adam,for practical training of GANs to enhance their generalization ***,we validate the effectiveness of the proposed algorithm through experiments conducted on bilinear games,multivariate Gaussian distributions,and the CelebA dataset,respectively.

关键词： GANs general bilinear game predictive centripetal acceleration algorithm lower and upper complexity bounds PCAA-Adam

维普期刊数据库

Study of K/Mn-MgO Supported Fe Catalysts with Fe（CO）5 and Fe（NO3）3 as Precursors for CO Hydrogenation to Light Alkenes

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2013年第10期31卷 1263-1268页

作者： liping tang Chengli Song Mengli Li Xiaolong Yang Bin Hu State Key Laboratory for Oxo Synthsis and Selective Oxidation Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou Gansu 730000 China University of Chinese Academy of Sciences Beijing 100049 China

Two K/Mn-MgO supported catalysts were prepared by Fe（CO）5 and Fe（NO3）3 as precursor respectively. The obtained Fe-K/Mn-MgO catalysts were tested for CO hydrogenation to light alkenes and characterized by X-ray powder diffraction （XRD）, X-ray photoelectron spectra （XPS）, H2 temperature-programmed reduction （H2-TPR）, H2 CO and CO2 temperature-programmed desorption （H2, CO/CO2-TPD） and transmission electron microscope （TEM） The results indicated that the catalyst with 10 wt% Fe loading prepared by Fe（CO）5 as precursor showed better performance in syngas to light alkenes than ones obtained from Fe（NO3）3 as precursor, where the CO conversion was 62.50% and the selectivity was 55.95% at 350 ℃, 1.5 MPa and 1000 h^-1, respectively.

关键词： iron precursor light alkenes CO conversion selectivity

Parameter sensitivity analysis of the axial stability for a marine flexible pipe

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum 2024年第3期10卷 548-556页

作者： liping tang Jiaxin Zou Kenan Song Yongheng Shi Li Liu School of Mechatronic Engineering Southwest Petroleum UniversityChengdu610500China School of Engineering University of AberdeenAberdeenAB243UEUK Oil&Gas Control Center National Petroleum and Natural Gas Pipeline Network Group Co.Ltd.Beijing100020China

Marine unbonded flexible pipes serve as the most essential equipment in offshore oil and gas exploration and *** compressive loads during installation or in service in the complex marine environment usually lead to buckling failure.A flexible pipe is a composite structure with multiple functional layers,of which the tensile armor layer plays a key role with regard to the response of the pipe subjected to axial *** this paper,a simplified three-dimensional finite element model is developed,focusing on the tensile layer and replacing the carcass layer,pressure sheath layer,and pressure armor layer by a cylindrical rigid body to reduce computational *** using this model,the buckling failure modes of the tensile armor layer(in particular the birdcaging phenomenon)are *** key parameters that affect the stability of the flexible pipe under axial compression and torsion are emphasized,and their effects on its axial and torsional stiffness are compared and *** results show that both the lay angle of the steel wires and the interlayer friction coefficient have a significant influence on the axial and torsional stiffness of the pipe,whereas the damaged length of the outer sheath has virtually no effect.

关键词： Flexible pipe Tensile armor Buckling failure Key parameters Stiffness

On the formation of limit cycle of the friction-induced stick-slip vibration in oilwell drillstring

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum 2015年第1期1卷 63-67页

作者： Xiaohua Zhu liping tang School of Mechatronic Engineering Southwest Petroleum UniversityChengdu 610500China

In this paper,the stick-slip vibration in oilwell drillstring is *** drilling system is modelled as a lumped-parameter torsional pendulum and the interaction between the drill bit and the rock is treated as Coulomb *** of motion of the drill bit is established and the dynamic responses of the drill bit are obtained.A drilling system with the drillstring length 3000 m is analysed,in which the system parameters are selected by reference to the actual drilling *** the slip vibrations in the initial stage,final state of the drill bit is a stable stick-slip vibration of which the limit cycle is a closed *** order to find the stability of the limit cycle corresponds to the periodically stick-slip vibration,different initial conditions for the drill bit are *** show that the drill bit will lead to a periodic motion and the phase trajectories ultimately converge to the same limit cycle corresponds to stable stick-slip vibration.

关键词： Stick-slip vibration Friction Drillstring Drill bit Limit cycle

维普期刊数据库

Promotion of Mn Doped Co/CNTs Catalysts for CO Hydrogenation to Light Olefins

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2013年第6期31卷 826-830页

作者： liping tang Chengli Song Xiaolong Yang Mengli Li Bin Hu State Key Laboratory for Oxo Synthsis and Selective Oxidation Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou Gansu 730000 China University of Chinese Academy of Sciences Beijing 100049 China

With various contents, Mn was introduced into carbon nanotubes （CNTs） supported cobalt catalysts and the obtained Mn-Co/CNTs catalysts were investigated for CO hydrogenation to light alkenes and characterized by N2 ad- sorption, X-ray diffraction （XRD）, X-ray photoelectron spectra （XPS）, H2 temperature programmed reduction （TPR）, CO temperature programmed desorption （TPD） and transmission electron microscope （TEM）. The results indicate that the addition of a small amount of Mn （0.3 wt%） to CNTs-supported Co catalyst significantly increased the selectivity of C2--C4 olefins and decreased the selectivity of CH4. However, with further addition of Mn to the cobalt catalysts, the CH4 selectivity decreased obviously along with the increase of the C5 selectivity. Compared with the unpromoted catalysts, the Mn-promoted cobalt catalysts increased the C2=-C4=/C20- C40 molar ratio.

关键词： CO hydrogenation cobalt catalyst light alkenes selectivity

The distribution of the oil derived from Cambrian source rocks in Lunnan area,the Tarim Basin,China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2007年第A1期52卷 133-140页

作者： MI JingKui ZHANG ShuiChang CHEN JianPing tang liping HE ZhongHua Research Institute of Petroleum Exploration and Devlopment PetroChina Beijing 100083 China

There are great differences in biomarks between Cambrian oil and Middle-Upper Ordovician oil. In this stuty, the authors analyzed 40 oils found in Lunnan area by GC-MS and calculated the content of Cambrian oil in the 40 oils according to the steroid indexes of typical oil mixture and match experiment. The results show that it is a general phenomenon in Ordovician reservoir that the oil derived from Cambrian source rock mixed with the oil derived from Middle-Upper Ordovician source rock in Lunnan area, the mixture degree of the two oils is lower in Carboniferous reservoir than in Ordovician reservoir, and the oils kept in Triassic reservoir have single source, Middle-Upper Ordovician source rock. The mixture oils mainly composed of Cambrian oil (>50%) distributed in Sangtamu fault zone, and the oils found in Lunnan fault zone are Middle-Upper Ordovician oil. This distribution of oils in Lunnan area is owing to that Lunnan fault zone is located in anticline axis part, Lunnan fault zone underwent serious erosion, and the oils from Cambrian source rock accumulated in Lunnan fault zone were degraded completely during Caledonian-Hercynian movement. But the Cambrian oil accumulated in Sangtamu fault zone was not degraded completely and some of them were left for the location of Sangtamu fault zone is lower than Lunnan fault zone. Later, the oil derived from Middle-Upper Ordovician source rock mixed with the remained Cambrian oil, and the mixture oil formed in Sangtamu fault zone.

关键词：塔里木盆地寒武纪油气混合物类固醇

A DUAL-MODALITY OPTICAL BIOPSY APPROACH FOR IN VIVO DETECTION OF PROSTATE CANCER IN RAT MODEL

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Innovative Optical Health Sciences 2011年第3期4卷 269-277页

作者： VIKRANT SHARMA NIMIT PATEL JINHUI SHEN liping tang GEORGE ALEXANDRAKIS HANLI LIU Department of Bioengineering Joint Graduate Program between University of Texas at Arlington and University of Texas Southwestern Medical Center University of Texas at Arlington TX 76019USA

Ultrasound-guided biopsy procedure for prostate cancer diagnosis,which is the current gold standard,involves quasi-random sampling of prostate tissue without any functional *** this study,we discuss the possibility to augment the detection of prostate cancer using a dual-modality optical approach,which can be coupled with the current needle biopsy *** techniques are light reflectance spectroscopy(LRS)that uses a broadband light source and a CCD array spectrometer,and auto-fluorescence lifetime measurement(AFLM)that uses a custom-designed,time-correlated single photon counting(TCSPC)*** LRS and AFLM were employed sequentially in this study to measure cancer tissue along with control tissue on a rat prostate tumor *** an excitation wavelength of 447 nm,we investigated auto-fluorescence decay curves at the emission wavelengths of 532,562,632 and 684 nm for in vivo and ex vivo *** results show that auto-fluorescence lifetimes at all measured emission wavelengths differ between control and cancerous tissues with 100% specificity and ***,absolute values of hemoglobin derivatives and scattering coe±cient were quantified using in vivo *** part of study also demonstrates that light scattering and absorption are significantly different between the control and cancerous ***,the study demonstrates that both LRS and AFLM may provide several intrinsic biomarkers for in vivo detection of prostate cancer.

关键词： Prostate cancer light reflectance spectroscopy auto-fluorescence lifetime

Metagenomics reveals contrasting energy utilization efficiencies of captive and wild camels(Camelus ferus)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2022年第3期17卷 333-345页

作者： liping YAN liping tang Zhichao ZHOU Wei LU Bo WANG Zhicheng SUN Xue JIANG Defu HU Junqing LI Dong ZHANG School of Ecology and Nature Conservation Beijing Forestry UniversityBeijingChina Gansu Endangered Animals Protection Center WuweiChina Administrative Bureau of Dunhuang Xihu National Nature Reserve DunhuangChina

Captive conditions can affect the symbiotic microbiome of *** this study,we compared the structural and functional differences of the gastrointestinal microbiomes of wild Bactrian camels(Camelus ferus)between wild and captive populations,as well as their different host energy utilization performances through *** results showed that wild-living camels harbored more microbial taxa related to the production of volatile fatty acids,fewer methanogens,and fewer genes encoding enzymes involved in methanogenesis,leading to higher energy utilization efficiency compared to that of captive-living *** findings suggest that the wild-living camel fecal microbiome demonstrates a series of adaptive characteristics that enable the host to adjust to a relatively barren field *** study provides novel insights into the mechanisms of wildlife adaptations to habitats from the perspective of the microbiome.

关键词： adaptability energy utilization gastrointestinal microbiome metagenomics wild and captive wild Bactrian camel