检索结果-南通市图书馆

Wire Arc Additive Manufactured CuMn_(13)Al_(7)High-Manganese Aluminium Bronze

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Mechanical Engineering 2022年第5期35卷 382-392页

作者： chun Guo Baisong Hu Baoli Wei Feng Chen College of Mechanical Engineering Anhui Science and Technology UniversityBengbu 233000China

In this work,high-manganese aluminium bronze CuMn_(13)Al_(7)samples were prepared by arc additive manufacturing *** phase composition,microstructure,and crystal structure of the high-manganese aluminium bronze CuMn_(13)Al_(7)arc additive manufactured samples were analysed using direct-reading spectrometer,metallographic microscope,scanning electron microscope,and transmission electron *** micro-hardness tester,tensile tester,impact tester,and electrochemical workstation were also used to test the performance of the CuMn_(13)Al_(7)*** studying the microstructure and properties of the CuMn_(13)Al_(7)samples,it was found that preparation of the samples by the arc additive manufacturing technology ensured good forming quality,almost no defects,and good metallurgical bonding inside the *** metallographic structure(α+β+point phase)mainly comprises the following:the metallographic structure in the equiaxed grain region has an obvious grain boundaryα;the metallographic structure in the remelting region has no obvious grain boundaryα;the thermal influence on the metallographic structure produced a weaker grain boundaryαthan the equiaxed grain *** transverse and longitudinal cross sections of the sample had uniform microhardness distributions,and the average microhardness values were 190.5 HV0.1 and 192.7 HV0.1,*** sample also had excellent mechanical properties:yield strength of 301 MPa,tensile strength of 633 MPa,elongation of 43.5%,reduction of area by 58%,Charpy impact value of 68 j/cm^(2)at–20℃,and dynamic potential polarisation curve test ***,it was shown that the average corrosion potential of the sample was–284.5 mV,and the average corrosion current density was 4.1×10–3 mA/cm^(2).

关键词： CuMn_(13)Al_(7) High-manganese aluminium bronze Wire arc additive manufacturing Microstructure Mechanical properties

在线全文

学校读者我要写书评

暂无评论

社区基金初创期的行动困境与突破路径

山东行政学院学报 2024年第4期 90-99页

作者：黄春蕾李明叶山东大学哲学与社会发展学院济南250100 济南市基爱社会工作服务中心济南250100

初创期是社区基金存续的关键,也是其全生命周期健康运行的基础。对山东省j市的调查发现,社区基金存在实际支出少、公众动员和项目传播被后置、筹款和支出缺乏内驱力三大困境。j市社区基金困境的突破受制于外部环境、直接环境和设定环境... 详细信息

初创期是社区基金存续的关键,也是其全生命周期健康运行的基础。对山东省j市的调查发现,社区基金存在实际支出少、公众动员和项目传播被后置、筹款和支出缺乏内驱力三大困境。j市社区基金困境的突破受制于外部环境、直接环境和设定环境三大约束,应加大政策激励引导,优化社区基金发展外部环境;激发内驱力,分类实施社区基金培育孵化赋能成长;健全社区基金治理结构,增强发起人项目管理能力;建构社区慈善生态,为社区基金发展创造“源头活水”,实现社区基金行稳致远。

关键词：社区基金行动困境环境约束组织外部控制慈善筹款

Rotational properties of the odd-Z transfermium nucleus ^(255)Lr by a particle-number-conserving method in the cranked shell model

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2016年第7期59卷 25-32页

作者： Yu-chun Li Xiao-Tao He College of Material Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

Experimentally observed ground state band based on the 1/2-[521] Nilsson state and the first exited band based on the 7/2-[514] Nilsson state of the odd-Z nucleus 255Lr are studied by the cranked shell model （CSM） with the paring correlations treated by the particle-number-conserving （PNC） method. This is the first time the detailed theoretical investigations are performed on these rotational bands. Both experimental kinematic and dynamic moments of inertia （f^（1） and ,f^（2） versus rotational frequency are reproduced quite well by the PNC-CSM calculations. By comparing the theoretical kinematic moment of inertia f（1） with the experimental ones extracted from different spin assignments, the spin 17/2- →13/2- is assigned to the lowest-lying 196.6（5） keV transition of the 1/2- [521 ] band, and 15/2→11/2- to the 189（1） keV transition of the 7/2- [514] band, respectively. The proton N = 7 major shell is included in the calculations. The intruder of the high-j low→lj15/2 （1/2-[770]） orbital at the high spin leads to band-crossings at hω = 0.20 （hω~=0.25） MeV for the 7/2-[514]ω= -1/2 （ω= ＋1/2） band, and at hω=0.175 MeV for the 1/2- [521 ] ω= - 1/2 band, respectively. Further investigations show that the band-crossing frequencies are quadrupole deformation dependent.

关键词： rotational band spin assignment band-crossing high-j orbital transfermium nuclei

基于microRNA-21响应的Zn^(2+)/DNA自组装体用于肿瘤的检测和氧化应激治疗

在线全文

学校读者我要写书评

暂无评论

应用化学 2024年第1期41卷 164-174页

作者：徐昕李烨王敏傅章程齐国敏卢春华福州大学化学学院福州350116

DNA材料具有的特异性、可编程性和生物相容性,使得其在生物检测和药物递送方面具有很大的应用优势。为了进一步拓展DNA材料的应用和合成方法,本文报道了利用DNA与金属离子之间的配合作用,简单高效地制备具有肿瘤标志物micro RNA-21(mi R... 详细信息

DNA材料具有的特异性、可编程性和生物相容性,使得其在生物检测和药物递送方面具有很大的应用优势。为了进一步拓展DNA材料的应用和合成方法,本文报道了利用DNA与金属离子之间的配合作用,简单高效地制备具有肿瘤标志物micro RNA-21(mi R-21)响应性的Zn^(2+)/DNA自组装纳米粒子(ZDNPs)。通过粒子中DNA发卡结构与mi R-21的特异性互补,激活荧光信号并释放Zn^(2+),导致细胞内产生大量活性氧,从而用于肿瘤的荧光成像和氧化应激治疗。合成的ZDNPs为形状均匀的球形粒子,能有效对Zn^(2+)进行装载。通过ZDNPs对mi R-21的响应性实验,验证了ZDNPs与miR-21浓度之间具有良好的线性响应荧光信号,线性响应范围在5~160 nmol/L,检测限为5 nmol/L,且具备特异性。此外,本文对ZDNPs在细胞内的作用效果也进行了研究,结果表明其能在肿瘤细胞内进行响应性的荧光成像,并能通过氧化应激途径介导肿瘤细胞凋亡。在活体的荧光成像和肿瘤治疗中,ZDNPs在肿瘤病灶部位体现出特异性和持续性的示踪能力,并且对肿瘤产生了明显的生长抑制效果。

关键词： DNA发卡锌离子 microRNA-21 肿瘤成像氧化应激治疗

Boundedness of Caldero'n-Zygmund operators in product Hardy spaces

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A journal of Chinese Universities) 2009年第3期24卷 321-335页

作者： HAN Yong-sheng YANG Da-chun Department of Mathematics Auburn University Auburn AL 36849-5310 USA School of Mathematical Sciences Beijing Normal University Laboratory of Mathematics and Complex Systems Ministry of Education Beijing 100875 China (Corresponding author)

By means of vector-valued product Calderón-Zygmund operators and some subtle estimates,the boundedness in product Hardy spaces on R^n × R^m of Calderón-Zygmund operators introduced by j.L. journé is established.

关键词： Hardy space product domain Calderón-Zygmund operator vector-valued operator

Cosmological twinlike models with multi scalar fields

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2018年第9期61卷 31-36页

作者： Yuan Zhong chun E Fu Yu Xiao Liu School of Science Xi'an Jiaotong University Institute of Theoretical Physics Lanzhou University

In this study, we consider cosmological models driven by several canonical or noncanonical scalar fields, and we show the manner in which twinlike models for a canonical model can be constructed from noncanonical ones using the superpotential method. We conclude that it is possible to construct twinlike models for multifield cosmological models, even with a nonzero spatial *** work extends the discussions of [D. Bazeia, and j. D. Dantas, Phys. Rev. D 85, 067303(2012)] to cases with multi scalar fields and with non-vanished spatial curvature, by using a different superpotential method.

关键词： cosmological twinlike models superpotential method noncanonical scalar field

Effect of electromechanical the properties of epitaxial boundary conditions on ferroelectric thin films

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2011年第10期20卷 407-412页

作者： Zhou Zhi-Dong Zhang chun-Zu jiang Quan Department of Materials Science and Engineering College of Materials Xiamen University Xiamen 361005 China Department of Civil Engineering School of Architecture and Civil Engineering Xiamen University Xiamen 361005 China College of Civil Engineering Nantong University Nantong 226019 China

The effects of internal stresses and depolarization fields on the properties of epitaxial ferroelectric perovskite thin films are discussed by employing the dynamic Ginzbur~Landau equation （DCLE）. The numerical solution for BaTiO3 film shows that internal stress and the depolarization field have the most effects on ferroelectric properties such as polarization, Curie temperature and susceptibility. With the increase of the thickness of the film, the polarization of epitaxia] ferroelectric thin film is enhanced rapidly under high internal compressively stress. With the thickness exceeding the critical thickness for dislocation formation, the polarization increases slowly and even weakens due to relaxed internal stresses and a weak electrical boundary condition. This indicates that the effects of mechanical and electrical boundary conditions both diminish for ferroelectric thick films. Consequently, our thermodynamic method is a full scale model that can predict the properties of ferroelectric perovskite films in a wide range of film thickness.

关键词： ferroelectric film internal stresses thermodynamic equations polarizations

Economic and Political Factors that Lead to the Budget Deficit in Hong Kong from 1998 to 2003

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Population,Resources and Environment 2006年第4期4卷 9-17页

作者： Fan chun Wai The Centre for Information and Communication Technology in Education (CICTE) University of Macao Ay. Padre Tomas Pereira S.J. Taipa Macao China

Despite the adverse impact of the budget deficit in Hong Kong has been alleviated since the economic recovery from 2003, the fiscal deficit may return when there is another downturn in the economy if the problem is not handled *** on the economic and political situation from 1998 to 2003,the factors that lead to the budget deficit in Hong Kong are analyzed in four perspectives,including(a)increase in public expenditure;(b)decrease in public revenues;(c)poor management of public money and(d) weak *** a better understanding on these factors, possible solutions to the fiscal problem faced by the government may be developed.

关键词： government budget budget deficit fiscal policy government revenue

Reoxidation process and corrosion behavior of TA15 alloy by laser ablation

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2021年第4期40卷 865-876页

作者： Bo-Wen Liu Gao-Yang Mi chun-Ming Wang School of Materials Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China

The thermal oxide layer formed of TA15 alloy has poor corrosion *** this paper,the changes of the elements and components on the surface after laser ablation with different energy densities(E) were *** formation process and corrosion behavior of laser-generated oxide layer were *** E increases,the oxygen content decreases from 8.52% to 5.43% and then increases to 11.89%.The surface oxide layer changes from TiO_(2)(R)(i.e.,rutile) to Ti_(2) O_(3)+TiO_(2)(R) and finally becomes TiO_(2)(R)+TiO_(2)(A)(i.e.,anatase).The TiO_(2)(R) gasification was confirmed by calculating the surface temperature *** surface reoxidation process was illustrated by a thermodynamically calculated ΔGT(i.e.,the Gibbs free energy changes with temperature).When E≥17.5 j·cm^(-2),the oxide layer exhibits an agitated morphology,and oxide falls off at the *** E increases,the corrosion rate decreases first and then *** energy density of 8.75 j·cm^(-2),the surface corrosion rate was 20.43 times slower than that of the untreated *** impedance spectrum and equivalent resistance results also prove the best corrosion resistance at 8.75 j·cm^(-2).The corrosion behavior of the oxide layer is analyzed from the properties of the oxide layer components and the reaction products with the electrolyte.

关键词： Laser ablation TA15 alloy Reoxidation process Corrosion behavior Elemental analysis