检索结果-南通市图书馆

hydro-mechanical behavior of an argillaceous limestone considered as a potential host formation for radioactive waste disposal

引用

Journal of Rock mechanics and Geotechnical Engineering 2018年第6期10卷 1063-1081页

作者： T.S.Nguyen Zhenze Li Grant Su m.h.b.nasseri R.P.Young Canadian Nuclear Safety Commission OttawaCanada Department of Civil Engineering University of TorontoTorontoCanada

The Canadian Nuclear Safety Commission(CNSC), Canada’s nuclear regulator, conducts regulatory research in order to develop independent knowledge on safety aspects related to the deep geological disposal of radioactive wastes. In Canada, the Cobourg limestone of the michigan basin is currently considered as a potential host formation for geological disposal. The understanding of the hydromechanical behavior of such a host rock is one of the essential requirements for the assessment of its performance as a barrier against radionuclide migration. The excavation of galleries and shafts of a deep geological repository(DGR) can induce damage to the surrounding rock. The excavation damaged zone(EDZ) has higher permeability and reduced strength compared to the undisturbed rock and those factors must be considered in the design and safety assessment of the DGR. The extent and characteristics of the EDZ depend on the size of the opening, the rock type and its properties, and the in situ stresses, among other factors. In addition, the extent and characteristics of the EDZ can change with time due to rock strength degradation, evolution of fractures within the EDZ, and the redistribution of pore pressure around the excavation. In this research project initiated by the CNSC, the authors conducted experimental and theoretical research in order to assess the hydro-mechanical behavior of the Cobourg limestone under undamaged and damaged conditions, both in the short and long terms. The short-term behavior was investigated by a program of triaxial tests with the measurement of permeability evolution on specimens of Cobourg limestone. The authors formulate a coupled hydro-mechanical model to simulate the stress-strain response and evolution of the permeability during those triaxial tests. Using creep and relaxation data from a similar limestone, the model was extended to include its long-term strength degradation. The model successfully simulated both the short-and long-term hydro-me

关键词： hydro-mechanical behavior Excavation damage Deep geological repository(DGR) Limestone Poro-elasto-plasticity

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

Antimonene-based saturable absorber for a soliton mode-locked and Q-switched fiber laser in the 2 μm wavelength region

引用

Chinese Physics b 2023年第6期32卷 259-269页

作者： h Ahmad b Nizamani m Z Samion N Yusoff m F Ismail Photonics Research Centre Universiti Malaya50603 Kuala LumpurMalaysia Physics Department Faculty of ScienceUniversiti Malaya50603 Kuala LumpurMalaysia Distinguished Visiting Professor Universiti Kuala Lumpur British Malaysian Institute(UniKL BMI)Batu 8Jln Sungai Pusu53100SelangorMalaysia

We demonstrate antimonene as a saturable absorber(SA) to generate an ultrafast mode-locked and Q-switched laser in the 2 μm wavelength region. The two antimonene-based SAs were prepared and inserted separately in a thulium–holmiumdoped fiber laser to produce the pulsed laser. Antimonene was coated onto a tapered fiber to generate soliton mode-locked pulses and used in thin-film form for the generation of Q-switched pulses. The mode-locking was stable within a pump power of 267 m W–511 m W, and the laser operated at a central wavelength of 1897.4 nm. The mode-locked laser had a pulse width of 1.3 ps and a repetition rate of 12.6 mhz, with a signal-to-noise ratio of 64 d b. Q-switched laser operation was stable at a wavelength of 1890.1 nm within a pump power of 312 m W–381 m W. With the increase in pump power from 312 m W to 381 m W, the repetition rate increased to a maximum of 56.63 k hz and the pulse width decreased to a minimum value of 2.85 μs. Wide-range tunability of the Q-switched laser was also realized within the wavelength range of1882 nm–1936 nm.

关键词： mode-locking Q-switched fiber laser optical saturable absorber

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

holmium Oxide Film as a Saturable Absorber for 2μm Q-Switched Fiber Laser

引用

Chinese Physics Letters 2017年第5期34卷 48-51页

作者： m.F.A.Rahman m.F.m.Rusdi m.Q.Lokman m.b.h.mahyuddin A.A.Latiff A.h.A.Rosol K.Dimyati S.W.harun Department of Electrical Engineering University of Malaya Kuala Lumpur 50603 Malaysia Photonics Research Centre University of Malaya Kuala Lumpur 50603 Malaysia Faculty of Electrical Engineering University Teknologi Mara Shah Alam 40450 Malaysia

This work reports on the use of the holmium oxide （ho2O3） polymer film as a saturable absorber （SA） for generating stable Q-switching pulses operating in a 2μm region in a thulium-doped fiber laser cavity. The SA is prepared by diluting a commercial ho3O2 powder and then mixing it with polyvinyI alcohol （PVA） solution to form a ho2O3-PVA film. A tiny part of the film about 1mm×1 mm in size is sandwiched between two fiber ferrules with the help of index matching gel. When incorporated in a laser cavity driven by a 1552-nm pump, stable Q-switching pulses are observed at 1955nm within the pump power range of 363 491 roW. As the pmnp power increases within this range, the repetition rate rises from 26 khz to 39 khz, as the pulse width drops from 4.22μs to 2.57μs. The laser operates with a signal-to-noise ratio of 47db, and the maximum output power and the pulse energy obtained are 2.67mW and 69ng, respectively. Our results successfully demonstrate that the ho2O3 film can be used as a passive SA to generate a 2μm pulse laser.

关键词： m Q-Switched Fiber Laser SA FESEm

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

原位应力下裂缝性致密砂岩各向异性地震波速及其渗透率关联特征

引用

煤炭学报 2022年第1期47卷 246-258页

作者： XIA Kaiwen 李星齐春艳姚伟肖香姣张杰 nasseri m h b 天津大学水利仿真与安全国家重点实验室天津300072 多伦多大学土木与矿业工程学院加拿大多伦多M5S1A4 中国石油集团工程技术研究院有限公司北京102206 中国石油塔里木油田公司新疆库尔勒841000

超深层裂缝性非常规天然气藏的开发在能源领域所占比重越来越大,但目前关于该类型储层在原位应力下各向异性地震波速及渗透率的基础研究仍鲜有报道,一定程度上制约了其高效开发策略的制定进程。以塔里木油田克深2号裂缝性致密砂岩天然... 详细信息

超深层裂缝性非常规天然气藏的开发在能源领域所占比重越来越大,但目前关于该类型储层在原位应力下各向异性地震波速及渗透率的基础研究仍鲜有报道,一定程度上制约了其高效开发策略的制定进程。以塔里木油田克深2号裂缝性致密砂岩天然气储层为工程背景,利用先进的地球物理成像真三轴测试系统,开展了储层衰竭期间原位应力下完整砂岩与不同倾角裂缝岩样的各向异性地震波速以及各向异性渗透率演化规律实验研究,探讨了压缩波、剪切波、纵横波速比、3个主应力方向渗透率各向异性特性与内在机制,研究了地震波速与渗透率的内在关联特征。研究结果表明:首先,裂缝引起的结构非均质性以及三向不等应力作用下岩石各主应力方向微观结构的变形差异导致了地震波速的各向异性;储层衰竭期间地震波速度均随有效应力的增大近似线性增加,压缩波速度明显大于剪切波速度;纵横波速比随有效应力增大而单调减小,表明剪切波对外部荷载敏感性更强;通过压缩波速和纵横波波速比数据对比,发现剪切波S2速度对裂缝倾角更为敏感。其次,原位应力下各主方向渗透率均表现出显著的应力敏感性和结构(裂缝)敏感性,早期应力大小对储层衰竭中后期渗透率变化具有重要影响,渗透率各向异性随裂缝倾角减小而更加显著;与裂缝平面正(斜)交方向的渗透率相对比较平滑,而沿裂缝平面方向渗透率呈现出一定的波动特性,这主要是由于在压力流体冲刷和岩石骨架进一步受压变形双重作用下,破碎的微颗粒会在孔隙/裂隙中不断运移,造成岩石内部孔隙/裂隙周期性堵塞和疏通引起的。此外,在实验应力条件下(走滑应力状态),裂缝倾角越小,水平主应力方向上的地震波速度-渗透率相关性越不明显;最大与最小水平主应力方向上的地震波速度-渗透率关系应区分对待,最大水平主应力方向地震波速与渗透率的相关性明显优于最小水平主应力方向。

关键词：真三轴应力裂缝砂岩地震波速渗透率各向异性

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

mssbauer spectra of mnFe_(2-2x)Al_(2x)O_4(0≤x≤0.4) ferrites

引用

Journal of Central South University 2010年第6期17卷 1129-1132页

作者： bATOO K m KUmAR S PRAKASh R ALImUDDIN SONG J I ChUNG h JEONG h KOO b h LEE C G King Abdullah Institute for Nanotechnology King Saud UniversityRiyadh 11451Saudi Arabia School of Nano and Advanced materials Engineering Changwon National UniversityChangwon 641773Korea Department of mechanical Engineering Changwon National UniversityChangwon 641773Korea Department of Applied Physics Aligarh Muslim UniversityAligarh 202002India Department of Precision & mechanical Engineering and bK21 Eco-Friendly heat & Cooling Energy mechanical Research Team Gyeongsang National U niversityTongyeong 650160Korea

The effect of non-magnetic Al^3＋ ion doping on the magnetic properties of mnFe2-2x Al2xO4 （0 ≤x≤ 0.4） spinel ferrites was studied using moessbauer spectroscopy measurements at room temperature. From the moessbauer study, it is observed that the ：esolved hyperfine sextets are due to the distribution of Fe ions on the two sublattices of the spinel ferrites. The value of the isomer shift obtained from the fitting of the moessbauer spectra indicates that Fe ions are in ＋3 state. A paramagnetic doublet is observed at ：iegree of inversion x=0.4, superimposed on the hyperfine sextets, indicating that the super-exchange interaction A-b decreases due to ：he dilution of sublattice by Al^3＋ ions. The hyperfine magnetic field decreases at both interstitial sites of tetrahedral （A） and 3ctahedral （b） with the increase in Al concentration.

关键词： ferrites hyperfine interactions moessbauer spectroscopy isomer shift

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

Attuned design of demand response program and m-FACTS for relieving congestion in a restructured market environment

引用

Frontiers in Energy 2015年第3期9卷 282-296页

作者： Y. hAShEmI h. ShAYEGhI b. hAShEmI Technical Engineering Department University of Mohaghegh Ardabili Ardabil *** Iran Network Studies Group Bakhtar Regional Electric Company Arak *** Iran

This paper addresses the attuned use of multi- converter flexible alternative current transmission systems （m-FACTS） devices and demand response （DR） to perform congestion management （Cm） in the deregulated environment. The strong control capability of the m- FACTS offers a great potential in solving many of the problems facing electric utilities. besides, DR is a novel procedure that can be an effective tool for reduction of congestion. A market clearing procedure is conducted based on maximizing social welfare （SW） and congestion as network constraint is paid by using concurrently the DR and m-FACTS. A multi-objective problem （mOP） based on the sum of the payments received by the generators for changing their output, the total payment received by DR participants to reduce their load and m-FACTS cost is systematized. For the solution of this problem a nonlinear time-varying evolution （NTVE） based multi-objective particle swarm optimization （mOPSO） style is formed. Fuzzy decision-making （FDm） and technique for order preference by similarity to ideal solution （TOPSIS） approaches are employed for finding the best compromise solution from the set of Pareto-solutions obtained through multi-objective particle swarm optimization-nonlinear time-varying evolution （mOPSO-NTVE）. In a real power system, Azarbaijan regional power system of Iran, comparative analysis of the results obtained from the application of the DR ＆ unified power flow controller （UPFC） and the DR ＆ m-FACTS are presented.

关键词： multi-converter flexible alternative currenttransmission systems (m-FACTS) demand response,

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

Nonlinear forced vibration in a subcritical regime of a porous functionally graded pipe conveying fluid with a retaining clip

引用

Applied mathematics and mechanics(English Edition) 2025年第1期46卷 101-122页

作者： m.GhOLAmI m.EFTEKhARI Department of mechanical Engineering Shahid Bahonar University of Kerman

This study examines the nonlinear behaviors of a clamped-clamped porous pipe made of a functionally graded material(FGm) that conveys fluids and is equipped with a retaining clip, focusing on primary resonance and subcritical dynamics. The nonlinear governing equations for the FGm pipe are derived by the extended hamilton's principle, and subsequently discretized through the application of the Galerkin *** direct method of multi-scales is then used to solve the derived equations. A thorough analysis of various parameters, including the clip stiffness, the power-law index, the porosity, and the clip location, is conducted to gain a comprehensive understanding of the system's nonlinear dynamics. Through the analysis of the first natural frequency, the study highlights the influence of the flow velocity and the clip stiffness, while the comparisons with metallic pipes emphasize the role of FGm composition. The examination of the forced response curves reveals saddle-node bifurcations and their dependence on parameters such as the detuning parameter and the power-law index, offering valuable insights into the system's nonlinear resonant behavior. Furthermore, the frequency-response curves illustrate the hardening nonlinearities influenced by factors such as the porosity and the clip stiffness, revealing nuanced effects on the system response and resonance characteristics. This comprehensive analysis enhances the understanding of nonlinear behaviors in FGm porous pipes with a retaining clip, providing key insights for practical engineering applications in system design and optimization.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The sexually dimorphic expression of glutamate transporters and their implication in pain after spinal cord injury

引用

Neural Regeneration Research 2025年第11期20卷 3317-3329页

作者： Jennifer m.Colón-mercado Aranza I.Torrado-Tapias Iris K.Salgado Jose m.Santiago Samuel E.Ocasio Rivera Dina P.bracho-Rincon Luis h.Pagan Rivera Jorge D.miranda Department of Physiology University of Puerto RicoMedical Sciences CampusSan JuanPRUSA National Institutes of health National Human Genome Research InstituteBethesdaMDUSA Universidad Central del Caribe School of MedicineBayamónPRUSA University of Puerto Rico Carolina CampusCarolinaPRUSA Institute of Neurobiology San JuanPRUSA

In addition to the loss of motor function,~60% of patients develop pain after spinal cord *** cellular-molecular mechanisms are not well understood,but the data suggests that plasticity within the rostral,epicenter,and caudal penumbra of the injury site initiates a cellularmolecular interplay that acts as a rewiring mechanism leading to central neuropathic *** can lead to the formation of new connections triggering abnormal sensory *** excitatory glutamate transporters are responsible for the reuptake of extracellular glutamate which makes them a critical target to prevent neuronal hyperexcitability and *** previous studies showed a sexually dimorphic therapeutic window for spinal cord injury after treatment with the selective estrogen receptor modulator *** this study,we investigated the anti-allodynic effects of tamoxifen in male and female rats with spinal cord *** hypothesized that tamoxifen exerts anti-allodynic effects by increasing the expression of glutamate transporters,leading to reduced hyperexcitability of the secondary neuron or by decreasing aberrant *** and female rats received a moderate contusion to the thoracic spinal cord followed by subcutaneous slow-release treatment of tamoxifen or matrix pellets as a control(placebo).We used von Frey monofilaments and the“up-down method”to evaluate mechanical *** treatment decreased allodynia only in female rats with spinal cord injury revealing a sexdependent *** expression profile of glutamatergic transporters(excitatory amino acid transporter 1/glutamate aspartate transporter and excitatory amino acid transporter 2/glutamate transporter-1)revealed a sexual dimorphism in the rostral,epicenter,and caudal areas of the spinal cord with a pattern of expression primarily on *** rodents showed a significantly higher level of excitatory amino acid transporter-1 expression while male rodents showed increased

关键词： allodynia central neuropathic pain EAAT-1/GLAST EAAT-2/GLT-1 glutamate transporters selective estrogen receptor modulator sexual dimorphism spinal cord injury trauma

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

Impurity effects on electrical conductivity of doped bilayer graphene in the presence of a bias voltage

引用

Chinese Physics b 2016年第7期25卷 316-323页

作者： E Lotfi h Rezania b Arghavaninia m Yarmohammadi Department of Physics Sanandaj Branch Islamic Azad University Department of Physics Razi University Department of Physics Kermanshah Branch Islamic Azad University Young researchers and Elite Club Kermanshah Branch Islamic Azad University

We address the electrical conductivity of bilayer graphene as a function of temperature, impurity concentration, and scattering strength in the presence of a finite bias voltage at finite doping, beginning with a description of the tight-binding model using the linear response theory and Green＇s function approach. Our results show a linear behavior at high doping for the case of high bias voltage. The effects of electron doping on the electrical conductivity have been studied via changing the electronic chemical potential. We also discuss and analyze how the bias voltage affects the temperature behavior of the electrical conductivity. Finally, we study the behavior of the electrical conductivity as a function of the impurity concentration and scattering strength for different bias voltages and chemical potentials respectively. The electrical conductivity is found to be monotonically decreasing with impurity scattering strength due to the increased scattering among electrons at higher impurity scattering strength.

关键词： bilayer graphene Green's function electrical conductivity

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

Suitability of lost cores in rheocasting process

引用

中国有色金属学会会刊：英文版 2010年第S3期20卷 948-953页

作者： h.mIChELS m.büNCK A.bühRIG-POLACZEK Giesserei-Institut RWTh Aachen Intzestraeβ5Aachen 52072Germany

When treated in pressure die casting processes the semi-solid aluminum alloys demand resilient cores which can bear the stress occurring during filling and the final pressure *** design of permanent cores is highly restricted in order to maintain *** cores provide the possibility of complex,undercut geometrical shapes which is mandatory for a variety of casting ***,eligible materials which show appropriate resilience and proper decomposition properties at the same time,and in the upper echelon of cost-effectiveness,are seldom *** the semi-solid process suited between hPDC and GDC regarding the core stress,several common and economically efficient lost core systems could be used.A selection of potentially suitable materials was identified and *** range of testing comprises widespread sand core-systems(amin-pur-coldbox and CO2-water-glass) as well as materials less commonly used,namely salt,plastic and *** types of conditioning are applied to enhance the surface *** mechanical properties of the sand cores are enhanced by different heat treatment methods during *** cores are tested producing a research component cast on a hPDC machine with semi-solid A356 slurry fabricated in the cooling channel *** cast component was analyzed regarding shape stability,core removability and surface as well as the structure *** results show the importance of the surface conditioning for the sand-cores while salt and zinc produce good parts comparable to the reference steel core quality.

关键词： aluminum semi-solid rheocasting cooling channel lost core sand salt zinc plastic

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

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：