检索结果-南通市图书馆

Time-dependent borehole stability in hard-brittle shale

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2022年第2期19卷 663-677页

作者： chuan-liang yan Lei-Feng Dong Kai Zhao Yuan-Fang Cheng Xiao-Rong Li Jin-Gen Deng Zhen-Qi Li Yong Chen Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)) Ministry of EducationQingdao266580ShandongChina School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina College of Petroleum Engineering Xi©an Shiyou UniversityXi©an710065ShaanxiChina State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China

Rock damage appears in brittle shale even prior to peak stress(i.e.,before failure)due to the occurrence of microcracks in these *** this work,a coupled hydromechanical model was built by incorporating the mechanical and fluid seepage induced stresses around a wellbore during *** borehole instability mechanism of hard-brittle shale was *** results show that even if a well is simply drilled into a hard-brittle shale formation,the formation around the borehole can be subjected to rock *** maximum failure ratio of the formation around the borehole increases with drilling time.A lower drilling fluid density corresponds to a faster increase in the failure ratio of the borehole with time and a shorter period of borehole *** the initial drilling fluid density is too low,serious rock damage occurs in the formation around the *** though a high-density drilling fluid is used after drilling,long-term borehole stability is difficult to *** drilling in hard-brittle shale,drilling fluid with a proper density should be used rather than increasing the density of the drilling fluid only after borehole collapse occurs,which is more favorable for maintaining long-term borehole stability.

关键词： Shale Rock damage Drilling fluid density Borehole stability

Carbon felt electrode coated with WS2 enables a high-performance polysulfide/ferricyanide flow battery

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第10期43卷 5039-5047页

作者： liang-Yu Li Su yan Ying-Jia Huang Fang-Fang Zhong Jin-Chao Cao Mei Ding chuan-Kun Jia College of Materials Science and Engineering Changsha University of Science and Technology Institute of Energy Storage Technology College of Energy and Power EngineeringChangsha University of Science and Technology Binzhou Institute of Technology Weiqiao-UCAS Science and Technology Park

Polysulfide/ferricyanide flow batteries （S/Fe RFBs）,with the advantages of abundant earth reservation low cost,high safety,and environmental friendliness,have attracted significant interest and demonstrated noteworthy potential for practical ***,the battery performance,including the energy efficiency （EE）,voltage efficiency （VE）,and power density of the S/Fe RFBs remains low owing to the slow redox kinetics of polysulfide *** address these concerns,WS2was selected as the booster and deposited on a commercial carbon felt electrode （WS2–CF） to stimulate the redox reactions of polysulfide *** better hydrophilicity and smaller charge-transfer resistance,WS2–CF exhibits enhanced electrochemical activity toward polysulfide redox ***,the battery performance of S/Fe RFB with WS2–CF as the anode has been improved,with EE of 84%,VE of 84%,and a peak power density of 175.7 mW·cm-2,which are all higher than the cell only with the bare carbon felt （CF） as electrodes (76%,77% and 155.8 mW·cm-2,respectively).Furthermore,the cycling life of the S/Fe RFB with WS2–CF has been prolonged to 2200 cycles with a capacity retention of 96% a 40 mA·cm-2because of the good stability of WS2–CF as the ***,under the same conditions,the S/Fe RFB without WS2–CF terminated after 1500 cycles with a fast capacity *** successful utilization of WS2as a booster on an electrode provides an efficient strategy for obtaining advanced S/Fe RFBs for practical applications.

关键词： Carbon felt Energy storage Polysulfide/ferricyanide flow battery Tungsten disulfide

Recognition and rejection of foreign eggs of different colors in Barn Swallows

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Avian Research 2024年第3期15卷 374-378页

作者： Kui yan Wei liang Ministry of Education Key Laboratory for Ecology of Tropical Islands Key Laboratory of Tropical Animal and Plant Ecology of Hainan ProvinceCollege of Life SciencesHainan Normal UniversityHaikou571158China

Brood parasitic birds lay eggs in the nests of other birds,and the parasitized hosts can reduce the cost of raising unrelated offspring through the recognition of parasitic *** can adopt vision-based cognitive mechanisms to recognize foreign eggs by comparing the colors of foreign and host ***,there is currently no uniform conclusion as to whether this comparison involves the single or multiple threshold decision *** this study,we tested both hypotheses by adding model eggs of different colors to the nests of Barn Swallows(Hirundo rustica)of two geographical populations breeding in Hainan and Heilongjiang Provinces in *** showed that Barn Swallows rejected more white model eggs(moderate mimetic to their own eggs)and blue model eggs(highly non-mimetic eggs with shorter reflectance spectrum)than red model eggs(highly nonmimetic eggs with longer reflectance spectrum).There was no difference in the rejection rate of model eggs between the two populations of Barn Swallows,and clutch size was not a factor affecting egg *** results are consistent with the single rejection threshold *** study provides strong experimental evidence that the color of model eggs can has an important effect on egg recognition in Barn Swallows,opening up new avenues to uncover the evolution of cuckoo egg mimicry and explore the cognitive mechanisms underlying the visual recognition of foreign eggs by hosts.

关键词： Barn Swallow Egg color Hirundo rustica Multiple rejection threshold Single rejection threshold Visual recognition system

Processing of a low-costγ-γ'NiPtAl coating with improved oxidation resistance

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第6期43卷 2832-2841页

作者： yan Jiang liang-liang Wei Jian He Hong-Bo Guo School of Materials Science and Engineering Beihang UniversityBeijing 100191China Key Laboratory of High-Temperature Structural Materials and Protective Coatings Ministry of Industry and Information TechnologyBeihang UniversityBeijing 100191China

A novelγ-γ'(Ni solid solution—Ni_(3)Al)NiPtAl coating was produced on advanced single-crystal(SC)superalloy N5 by electroplating of a thin Pt coating with~3μm in thickness followed by heat treatment at 1000℃in *** comparison,a traditionalγ-γ'NiPtAl coating was also produced by electroplating of a thick Pt coating with~6μm in thickness followed by heat treatment at 1100℃in *** novel coating has a mass gain of~0.5 mg·cm^(-2)after 100 h 1-h cyclic oxidation at 1150℃,showing better oxidation resistance than the traditional *** oxide scale mostly consisting ofα-Al_(2)O_(3)grew on the novel coating because the element Cr from the SC alloy substrate contributes to the formation ofα-Al_(2)O_(3).Pt content in the novel coating has significant effect on the oxidation *** optimized Pt content in the coating is about 16 at%,which is helpful to reduce the diffusion of harmful elements from the substrate into the coating but also to reduce the cost of the coating.

关键词： γ-γ'NiPtAl coating Platinum Oxidation Al_(2)O_(3) Superalloy

Mismatch loss analysis of solar array output power on stratospheric airship during flight

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第2期37卷 371-384页

作者： Siyu LIU Kangwen SUN Haoquan liang Xinzhe JI Tong ZOU chuan SHAN School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Yunnan Innovation Institute Beihang UniversityKunming 650233China Institute of Unmanned System Beihang UniversityBeijing 100191China

Stratospheric airships are long-endurance aerostats and have broad *** of the energy required for their operation is obtained from solar radiation,which makes accurate calculation of the energy output from the solar array crucial to the design and flight planning of the ***,the status of each photovoltaic module in the solar array may differ due to the airship curvature,resulting in mismatch losses and lowered output power,which has not been widely *** this paper,an irradiation model and a thermal model are established based on the actual arrangement of the *** output power model is established considering the non-uniform radiation in the *** mismatch losses of the array are analyzed under different flight *** output power of the solar array is decreased by up to 31.6%compared to the ideal ***,the proportion of mismatch losses increases with latitude,but the maximum mismatch loss power occurs at ***,an array reconfiguration method is proposed based on the irradiance dispersion index and position dispersion *** reconfigured array increases output power by 11.5%and can maintain energy balance in continuous *** results can be used to correct the overestimation of the output power during the airship design or to guide the configuration of the solar array.

关键词： Stratospheric airship Solar panels Solar energy Non-uniform irradiation Mismatch loss assessment Reconfiguration

An Accelerated Proximal Gradient Algorithm for Hankel Tensor Completion

在线全文

学校读者我要写书评

暂无评论

Journal of the Operations Research Society of China 2024年第2期12卷 461-477页

作者： chuan-Long Wang Xiong-Wei Guo Xi-Hong yan Key Laboratory of Engineering and Computational Science Shanxi Provincial Department of EducationJinzhong 030619ShanxiChina Department of Mathematics Taiyuan Normal UniversityJinzhong 030619ShanxiChina

In this paper,an accelerated proximal gradient algorithm is proposed for Hankel tensor completion *** our method,the iterative completion tensors generated by the new algorithm keep Hankel structure based on projection on the Hankel tensor ***,due to the special properties of Hankel structure,using the fast singular value thresholding operator of the mode-s unfolding of a Hankel tensor can decrease the computational ***,the convergence of the new algorithm is discussed under some reasonable ***,the numerical experiments show the effectiveness of the proposed algorithm.

关键词： Hankel tensor Tensor completion Accelerated proximal gradient algorithm

Research on casing deformation prevention technology based on cementing slurry system optimization

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

Petroleum Science 2024年第2期21卷 1231-1240页

作者： yan yan Meng Cai Wen-Hai Ma Xiao-chuan Zhang Li-Hong Han Yong-Hong Liu State Key Laboratory for Performance and Structure Safety of Petroleum Tubular Goods and Equipment Materials CNPC Tubular Goods Research InstituteXi©an710077ShaanxiChina College of Mechanical and Electrical Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Shale Gas Evaluation and Exploitation Key Laboratory of Sichuan Province Chengdu610095SichuanChina CNPC Daqing Oilfield Company Daqing163453HeilongjiangChina

The casing deformation prevention technology based on the optimization of cement slurry is proposed to reduce the casing deformation of shale oil and gas wells during hydraulic fracturing. In this paper, the fracture mechanism of hollow particles in cement sheath was firstly analyzed by discrete element method, and the effect of hollow particles in cement on casing deformation was investigated by laboratory experiment method. Finally, field test was carried out to verify the improvement effect of the casing deformation based on cement slurry modification. The results show that the formation displacement can be absorbed effectively by hollow particles inside the cement transferring the excessive deformation away from casing. The particles in the uncemented state provide deformation space during formation slipping. The casing with diameter of 139.7 mm could be passed through by bridge plug with the diameter of 99 mm when the mass ratio of particle/cement reaches 1:4. According to the field test feedback, the method based on optimization of cement slurry can effectively reduce the risk of casing deformation, and the recommended range of hollow microbeads content in the cement slurry is between 15% and 25%.

关键词： Cement slurry Hollow ceramsite Casing deformation Formation slip Field test

Resource allocation for D2D-assisted haptic communications

在线全文

学校读者我要写书评

暂无评论

Digital Communications and Networks 2024年第1期10卷 63-74页

作者： yan Wu Chao Yue yang yang liang Ao College of Telecommunication Engineering Army Engineering University of PLANanjing210000China

Haptic communications is recognized as a promising enabler of extensive services by enabling real-time haptic control and feedback in remote environments,e.g.,teleoperation and autonomous *** the strict transmission requirements on reliability and latency,Device-to-Device(D2D)communications is introduced to assist haptic *** particular,the teleoperators with poor channel quality are assisted by auxiliaries,and each auxiliary and its corresponding teleoperator constitute a D2D ***,the haptic interaction and the scarcity of radio resources pose severe challenges to the resource allocation,especially facing the sporadic packet ***,the contentionbased access scheme is applied to achieve low-latency transmission,where the resource scheduling latency is omitted and users can directly access available *** this context,we derive the reliability index of D2D pairs under the contention-based access scheme,i.e.,closed-loop packet error ***,the reliability performance is guaranteed by bidirectional power control,which aims to minimize the sum packet error probability of all D2D *** game theory is introduced to solve the problem with low ***,a distributed power control algorithm based on synchronous log-linear learning is proposed to converge to the optimal Nash *** results demonstrate the superiority of the proposed learning algorithm.

关键词： Haptic communications D2D Power control Contention-based access Potential game

Preparation and characterization of pH-responsive metal-polyphenol structure coated nanoparticles

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

Food Science and Human Wellness 2024年第3期13卷 1303-1310页

作者： Qile Xia yan liang Ailing Cao yan Cao Luyun Cai Key Laboratory of Post-Harvest Handling of Fruits Food Science InstituteZhejiang Academy of Agricultural SciencesHangzhou 310021China Ningbo Research Institute College of Biosystems Engineering and Food ScienceZhejiang UniversityNingbo 315100China School of Biological and Chemical Engineering Zhejiang Engineering Research Center for Intelligent Marine Ranch EquipmentNingboTech UniversityNingbo 315100China College of Food Science and Engineering Bohai UniversityJinzhou 121013China Hangzhou Customs District Hangzhou 310007China

In this paper,tannic acid(TA)and Fe~(3+)were added to form a layer of metal-polyphenol network structure on the surface of the nanoparticles which were fabricated by zein and carbon quantum dots(CQDs)encapsulating phlorotannins(PTN).pH-Responsive nanoparticles were prepared successfully(zein-PTN-CQDs-Fe-~Ⅲ).Further,the formation of composite nanoparticles was confirmed by a series of characterization *** zeta-potential and Fourier transform infrared spectroscopy data proved that electrostatic interaction and hydrogen bonding are dominant forces to form *** encapsulation efficiency(EE)revealed that metal-polyphenol network structure could improve the EE of *** analysis and differential scanning calorimetry experiment indicated the thermal stability of zein-PTN-CQDs-Fe~Ⅲnanoparticles increased because of metal-polyphenol network *** pH-responsive nanoparticles greatly increased the release rate of active substances and achieved targeted release.

关键词： Metal Phlorotannins Nanoparticles pH-Responsive Characterization