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1.
Manufacturing technologies for making advanced micro systems have been developing in a rapid pace recently. Research progress towards nanosized structures and devices opens up a whole new horizon for miniaturized system integration. Advances in this field will have an enormous societal impact and economic benefit in areas such as information technology, energy, healthcare, and many more. There has been an enormous scientific and industrial interest in nanosized advanced technologies. The theories, tools and practices for the design, manufacturing and test of these systems are emerging. The aim of this special section is to capture some of the latest developments in integration technologies for the micro/nanosystems, with the following topics： Molecular and crystal assembly inside the carbon nanotube： encapsulation and manufacturing approachesElectroplating for high aspect ratio vias in PCB manufacturing： enhancement capabilities of acoustic streaming Local synthesis of carbon nanotubes for direct integra tion in Si microsystemsdesign considerations Waferlevel SLID bonding for MEMS encapsulation Effect of substrates and underlayer on CNT synthesis by plasma enhanced CVD These papers will briefly highlight important advance ments in manufacturing technologies of the micro/nano systems, and outline the blueprint of upcoming information technology revolution from the manufacturing point of view. 相似文献
2.
Dynamical Behavior of Nonlinear Viscoelastic Timoshenko Beams with Damage on a Viscoelastic Foundation 总被引：2，自引：0，他引：2
Based on convolution-type constitutive equations for linear viscoelastic materials with damage and the hypotheses of Timoshenko beams with large deflections, the nonlinear equations governing dynamical behavior of Timoshenko beams with damage on viscoelastic foundation were firstly derived. By using the Galerkin method in spatial domain, the nonlinear integro-partial differential equations were transformed into a set of integro-ordinary differential equations. The numerical methods in nonlinear dynamical systems, such as the phase-trajectory diagram, Poincare section and bifurcation figure, were used to solve the simplified systems of equations. It could be seen that simplified dynamical systems possess the plenty of nonlinear dynamical properties. The influence of load and material parameters on the dynamic behavior of nonlinear system were investigated in detail. 相似文献
3.
Nowadays the modern females get out of home, fighting with males to display their wonderful life and demonstrate the wonderful characters, so we will ask the question what qualities do the modern females belong? By analyzing the novel Jane Eyre, it is easy to see the qualities of heroine such as independence, desiring of knowledge, exploring true love and emphasizing on spirit world and so on. This paper explains that it is important for modern females to build up their excellent qualities in order to deal with a lot of barriers in their future way. 相似文献
4.
INTRODUCTIONAt present, plastic as a substitute for metals in products is the most important mainstay in industrial raw materials. Furthermore, plastic injection molding is one of the most common and versatile methods for mass production of complex plastic parts with excel-lent dimensional tolerance. Since the technology of injection molding has been widely applied in manu-facturing, training on injection molding is of great importance. The traditional approach is to consult some technica… 相似文献
5.
Xizu Wang Durga Venkata Maheswar Repaka Ady Suwardi Qiang Zhu Jing Wu Jianwei Xu 《天津大学学报(英文版)》2023,(3):209-215
Liquid metal gallium has been widely used in numerous fields, from nuclear engineering, catalysts, and energy storage to electronics owing to its remarkable thermal and electrical properties along with low viscosity and nontoxicity. Compared with high-temperature liquid metals, room-temperature liquid metals, such as gallium(Ga), are emerging as promising alternatives for fabricating advanced energy storage devices, such as phase change materials, by harvesting the advantageous properties of the... 相似文献
6.
Numerical Derivation of Strain Rate Effects on Material Properties of Masonry with Solid Clay Bricks
In this paper, numerical method is used to study the strain rate effect on masonry materials. A typical unit of masonry is selected to serve as a representative volume element (RVE). Numerical model of RVE is established with detailed distinctive modeling of brick and mortar with their respective dynamic material properties obtained from laboratory tests. The behavior of brick and mortar are characterized by a dynamic damage model that accounts for rate-sensitive and pressuredependent properties of masonry materials. Dynamic loads of different loading rates are applied to RVE. The equivalent homogenized uniaxial compressive strength, threshold strain and elastic modulus in three directions of the masonry are derived from the simulated responses of the RVE. The strain rate effect on the masonry material with clay brick and mortar, such as the dynamic increase factor (DIF) of the ultimate strength and elastic modulus as a function of strain rate are derived from the numerical results. 相似文献
7.
The publication of the famous novel The Sound and The Fury projects the long-enduring reputation of William Faulkner as a household American writer in every nook and cranny of the world.Just in this novel,Faulkner employs the literary device of stream of consciousness and makes a good play with time and order to his own joy,which makes it an outstanding literary feature in the novel.In this essay,the unusual conceptions of time and order in the novel are tentatively probed mainly from the following three perspectives:1) the initiative for Faulkner creating the novel as a novel against time and order.2) the disordered arrangement as an artistic device——the optimum key to delivering the story.3) the potential order underlying the seeming disorder in the novel. 相似文献
8.
Numerical Derivation of Strain Rate Effects on Material Properties of Masonry with Solid Clay Bricks
WEI Xueying HAO Hong 《天津大学学报(英文版)》2006,12(B09):147-151
In this paper, numerical method is used als. A typical unit of masonry is selected to serve merical model of RVE is established with detailed to study the strain rate effect on masonry materias a representative volume element （RVE）. Nudistinctive modeling of brick and mortar with their respective dynamic material properties obtained from laboratory tests. The behavior of brick and mortar are characterized by a dynamic damage model that accounts for rate-sensitive and pressuredependent properties of masonry materials. Dynamic loads of different loading rates are applied to RVE. The equivalent homogenized uniaxial compressive strength, threshold strain and elastic modulus in three directions of the masonry are derived from the simulated responses of the RVE. The strain rate effect on the masonry material with clay brick and mortar, such as the dynamic increase factor （DIF） of the ultimate strength and elastic modulus as a function of strain rate are derived from the numerical results. 相似文献
9.
Nanostructures enhance phonon scattering and improve the figure of merit of thermoelectric materials. Nanosized CoSb3 skutterudite was synthesized by solvothermal methods using CoCl2 and SbCl3 as the precursors. A "two-step" model was suggested for the formation of CoSb3 based on the X-ray diffraction analysis. The first step is the formation of cobalt diantimonide in the earlier stage during the synthesis process. Diantimonide was then combined with antimony atoms to form the skutterudite structured triantimonide, CoSb3, in the later stage of the synthesis process as the second step. The synthesized CoSb3 powders consist of irregular particles with sizes of about 20 nm and sheets of about 80nm. 相似文献
10.
Review of the first principles calculations and the design of cathode materials for Li-ion batteries
Cathode materials are the most critical chal- lenge for the large scale application of Li-ion batteries in electric vehicles and for the storages of electricity. The first principles calculations play an important role in develop- ment and optimization of novel cathode materials. In this paper, we overview the first principles calculations of energy, volume change, band-gap, phase diagram, and Li- ion transport mechanism of cathode materials with an emphasis on the design of such materials. We also over- view the recent progress of data mining techniques and the high-throughput first principles calculations for the design and development of cathode materials. Finally, we preview the challenges and opportunities of this rapidly developing field. 相似文献
11.
Theoretical Calculation and Analysis of Slip and Deformation for Concrete Sandwich Panels 总被引：1，自引：0，他引：1
Slip and deformation of concrete sandwich panels under uniformly distributed loads is concerned. The effect of slip on the deformation of concrete sandwich panels are studied,and the analytical expressions of slip and deformation for concrete sandwich panels is obtained. These formulae can describe the slip distribution and account for its effect on deformation. In order to restrict the bound of formula, the formula of crack moment is obtained. The results of theoretical calculation are compared with those of tests and finite element methods. The comparison shows that the results of theoretical calculation are in accord with those of tests and finite element methods. So the theoretical calculation can be used to calculate slip and deformation of concrete sandwich panels in practical projects. 相似文献
12.
Network manufacturing has been rapidly developed and is going to play an important role in modern indusu‘y. The core of network manufacturing of mechanical products is the design and manufacturing based on the computer network technology. A network framework is introduced for manufacturing mechanical components at two main levels. On the design level features of the component are initially studied based on the structure and functions of the component. Details of the design procedure and contents are then analyzed with three main kinds of components. In this stage, selection of materials, calculation of sla‘ess and deflection under load, determination of the size are carried out using CAD. On the manufacturing level various aspects of CAPP are discussed, including the principle and the modes of positioning the component, the exerted clamping forces, cutting engagement and input parameters, machine tools used, and machining fluids if necessary. Finally a prototype of the network framework is presented with several pieces of data terminal equipment through a local area network, the topological structure, and data sharing and security, without concerning the use of the concurrent engineering techniques and virtual manufacturing, and virtual measuring techniques. 相似文献
13.
Discussion on the Cultivation of Nursing Faculties Based on the Development of Nursing Education in China 总被引：1，自引：0，他引：1
CAO Bao-hua XU Qiao-ling ZHANG Yin-ling LEI He 《美中教育评论》2007,4(1):53-57
The Chinese higher nursing education has developed fast. People＇s opinions to it have changed. In the future, it will show the developmental trends as follows. The scale of higher nursing education will be enlarged and educational levels will be improved continuously. The professional characteristics will be further focused on in nursing curriculum system. Teaching methods will be diversified to help the students to improve their abilities. The internationalization will be the developmental trend of nursing education. The development of nursing education puts forward higher demands for the faculties. How to cultivate the higher-quality nursing faculties has received increasing attention over the past few years as a common problem with serious consequences for the qualities of the students. It needs to equip the human resources of nursing teachers to be perfect, establish the academic faculty echelon and intensify the general qualities of nursing faculties. The nursing teachers should improve their theoretical and educational levels, develop the teaching capabilities, possess the capabilities of scientific research, enhance the clinical practical capabilities, improve the application abilities of the foreign language and cultivate the humanistic qualities to train the excellent students. 相似文献
14.
Cover-bearing-type bucket foundation for offshore wind turbines has been paid more and more attention due to its low cost and great bearing capacity. In order to ensure the cover-bearing mode, the muddy soil inside the bucket foundation should be reinforced by some soil consolidation methods, such as negative pressure and electro-osmosis. Firstly, tests were conducted to obtain the reasonable current density. Meanwhile, to improve the electro-osmotic speed and effectiveness, other factors such as intermittent power and layout of electrode, were also studied in the tests. Then, the soil reinforcing tests by negative pressure combined with electro-osmosis were performed for the muddy soil consolidation inside the bucket foundation. The results showed that soil reinforcement by negative pressure was quicker and more obvious during the early phase, and electro-osmotic method can affect more range of soil by rational arrangement of electrodes. Compared with negative pressure, the electro-osmotic method was a continuous and relatively slow process of reinforcement, which was complementary to the negative pressure method. The voltage value of electro-osmosis had little effect on the muddy soil reinforcement inside the bucket foundation, and 1.5 A was chosen as the most reasonable current value for scale model testing in the electro-osmotic method. 相似文献
15.
INTRODUCTION Cell encapsulation in biocompatible and semipermeable polymeric membranes is an effective method for immunoprotection, regardless of the type of recipient (allograft, xenograft, etc.). The semipermeable nature of the membrane prevents high molecular weight molecules, antibodies and other immunologic moieties from coming into contact with the encapsulated cells and destroying them as foreign invaders, but permits the entry of nutrients and oxy- gen and the exit of therapeutic p… 相似文献
16.
Qi-Jie Zhao Peng Cao Da-Wei Tu 《上海大学学报(英文版)》2014,(1):3-12
Correctly coding materials and identifying characters marked on materials are very important for steel manufacturing industry to realize informatization management and intelligent manufacturing. However, the steel products manufacturing is often in a high temperature environment, and there are a lot of material storage and retrieval processes, workers are not easily close to the environment and complete tasks, so it is a great challenge to automatically mark and identify characters on the steel products. This paper presents a framework of label characters marking and management for steel materials, furthermore, a kind of marked characters online detection and tracking method has been provided based on machine vision. In addition, some experiments have been done in BaoSteel to mark characters on hot billets and recognize them in multi situations, and the results show that the proposed method is practical, and has provided a helpful exploration in obtaining accurate fundamental data for the intelligent manufacturing system in steelworks. 相似文献
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Laser welding is an established manufacturing technology for a large variety of automotive applications due to its attractive properties such as low heat input, high precision and fast welding speed. Especially when welding high strength steels, which are dominantly used in today＇s car body construction, the low heat input by laser welding bears significant advantages with regard to the properties of the weld seam. The exploitation of the full application potential of laser welding in mass production requires an appropriate manufacturing concept and corresponding auxiliary technologies. The present paper demonstrates the integration of laser welding into the surrounding manu- facturing concepts by a modular setup with different levels of automation. This approach offers flexible solutions for individual needs thereby optimizing investment cost, labor cost and productivity. Recently available laser sources enable exceptionally high welding speed on thin gauged sheet metals but require efficient material handling con- cepts to utilize the full speed potential. Industrial concepts are presented offering efficient material handling and high process robustness for mass production welding. 相似文献
19.
The study of the interfacial and bond behaviour of reinforced cement-based materials is important for understanding the mechanical behaviour of such composites. This paper presents extensive experimental, theoretical and finite element analyses of pull-out tests of galvanised steel strips with different geometries, in lightweight cement-based material blocks with different densities and mechanical properties. The theoretical model proposed here is capable of determining the pull-out strength and bond stress versus the slip relationship between components of reinforced cement-based materials. This bond-slip relationship is then implemented in finite element simulation through the user-defined subroutine of ABAQUS software. Based on the results, a trilinear bond-slip model is suitable for modelling the interface between a steel strip and a cement-based material interface. 相似文献
20.
A nonmetal transportation port with soft soil foundation of Tianjin New Harbor failed during construction in 1997. The soil properties and geological changes before and after landslide were investigated by in situ test means. The stability of the slope was estimated with several calculation methods, such as the simplified Bishop method and the non-circle analysis method. According to the investigation and analysis results, the factors that may cause the slope failure can be determined as follows： excessive excavating, violating the normal construction procedure, excessive pore water pressure during earlier piling and sudden water-level fluctuation in front of the slope. Measures to improve the soil foundation for reconstructing the port include strengthening the failed slope with vibro sand piles, filling up the crushed stone layer, dividing the excavation into four steps and driving piles by larger intervals. The port now has been successfully reconstructed and begun operation. 相似文献