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Ball grid array (BGA) has the characters of excellent heat dissipation and high mechanical strength to satisfy with the need of high density packaging of electro produces. However BGA faces some problems of complex viscoplastic deformation, difficult failure test and high repair cost. This paper establishes a complex multichip packaging module with lead-free solder ball SAC305 BGA solder ball based...
Based on the finite element approach and the strain gradient (SG) theory, this paper produced a study on factors of size effect and minimum cutting thickness phenomenon in the micro-cutting process. Mechanisms of micro-cutting focusing on its characteristics that include size effect, tool edge radius and minimum cutting thickness has been studied. A new constitutive relationship based on SG theory...
Adjustable carrier concentration is an attractive feature of semiconductor nanoparticle that allows its surface plasmon resonance to be tuned. While quasi-static treatment of the electromagnetic interactions with the charge species can account for the polarization process in a conductive nanoparticle, a full-wave solution of the Maxwell's equations is needed to give a realistic portrait of the current...
Stereoscopic Warehouse plays an important role in the modernization of the logistics field. It is characterized by an informatization, automation, high efficiency, and often used in regional distribution center. In some special occasions or due to special field, the stereoscopic warehouse must be with tandem storage space in the reason that putting all of the racks parallelly in a single storage requires...
The electrical conductivity in semiconductors vs. temperature (Mott's equation) can be described by some nonlinear functional equations of the transcendental type. In this paper, the problem of finding the exact analytical closed-form solution for Mott's equation is studied, in some detail, by the Special Trans Functions Theory — STFT. The numerical results and graphical presentations confirm validity...
The work described in this conference talk follows up recent work on the development of a test for lack of field emission orthodoxy. There are three stages of discussion involved. First, the results of applying the test to 17 selected published FN plots are reported. About half fail the test, showing that related published field enhancement factor (FEF) values are unreliable. In several cases, this...
To investigate the expected improvement in oncurrent and sub-threshold slope in III-V heterostructure tunnel field-effect transistors, we assess the band-to-band tunneling probability using a one-dimensional model based on the envelope function approximation. We present results for two-layer heterostructure diodes and compare them to the results of a commercial semi-classical simulator (based on Kane's...
This paper explores the effective permittivity and permeability of the structure which has periodic lossy dielectric objects embedded in a matrix. The asymptotic expressions for both high conductivity and quasi-static are derived and discussed. Numerical results both from the MG formula and an integral equation approach are provided to verify all the asymptotic expressions and related conclusions.
The drift-diffusion approach is used to form an integro-differential equation for scattering problems involving three dimensional wire medium objects. The method is applicable to arbitrary three dimensional uniaxial and isotropic geometries. A spherical isotropic wire medium and a cubical uniaxial wire medium object are simulated numerically using the drift-diffusion method. The results are compared...
A new first-principles based volume integral equation (VIE) formulation is developed for the broadband fullwave extraction of 3-D circuits, containing arbitrarily shaped lossy conductors with inhomogeneous dielectrics. It accentuates all the advantages of the VIE formulation traditionally developed for solving wave-related problems, while facilitating circuit parameter extraction such as impedance...
Charge packet under high electric dc fields has been observed in polyethylene and its formation has been closely associated with ageing and breakdown of the insulating material. To understand the mechanisms several models have been proposed. In this paper, two models originated from completely different approaches have been reviewed. The first model proposed is based on bipolar charge injection together...
The influence of compositional fluctuations of N in GaInNAs Quantum Well (QW) lasers has been studied using a rate equation model. These fluctuations can be treated as Quantum-Dot (QD)-like fluctuations at the Conduction Band Edge (CBE). The gain model includes the QW material gain derived using a Band Anti-Crossing (BAC) model and includes QD fluctuations in the conduction band. For low N, (N ∼ 1%),...
Erbium doped silicon dioxide (Er3+: SiO2) was obtained by the sol-gel method. Efficient green and red upconversion luminescence was observed using 488 nm (70 mW, continuous wave) and 800 nm (25 ns pulsed) excitation. Upconversion study of luminescence was done for 3 different samples (1%, 4%, 10%: Er3+) of sol-gel SiO2. A theoretical analysis was performed and the results obtained were compared with...
The development of shale gas reserves is the current hotspot of oil and gas exploration and development at home and abroad. Correctly estimated reserves of gas reservoir has become increasingly urgent. The estimated of shale gas reservoir dynamic reserves in the past did not consider the influence of adsorbed phase occupies volume. In order to estimate the shale gas reservoir dynamic reserves exactly,...
The need of the tracking system for solar photovoltaic panel arises to extract maximum solar energy. This paper involves the mathematical simulation and control of fixed, single and dual axis solar tracking system for solar photovoltaic panel. The tracking system can be installed in the regions considered rich in solar energy. The dual axis solar photovoltaic panel is characterized by the capability...
This paper presents a new method for determining original gas in place and cumulative water influx in waterdrive gas reservoirs. The new method proposed in this paper mainly comprises four procedures: firstly, using the well test analysis results of non-stablized well test which was measured under the initial condition that waterdrive gas reservoir did not produce water, combining with current performance...
The non-destructive technique (NDT) such as for determined the velocity is an easy technique to apply and they are increasingly being used in geotechnical engineering. Most researchers studied the relations between rock properties and velocity and found that the velocity is closely related with rock properties. Wave velocity can be measured directly or indirectly in the laboratory. In this study,...
The systropic sphere is a spherical scatterer whose axes of anisotropy are defined by spherical coordinates. This contribution discusses the electrostatic scattering from a systropic sphere with extreme material parameters. The permittivity divides into three component in the spherical coordinates. Larger component values produce more polarizability, but there is a limit to the increase of the polarizability...
A mixed volume-surface integral equation (VSIE) solution for complex composite structures is presented. The structures can contain different boundaries such as PEC, PMC, DB, and D′B′ as well as general anisotropic media with permittivity and permeability dyadics differ from those of background. The L2-conforming volume integral equation (VIE) method is applied for penetrable domains (inhomogeneous...
A hybrid FDTD update scheme for cylindrical meshes is proposed in order to overcome limitations on the maximum stable time step that arise from inherently small grid steps. The algorithm combines the advantages of explicit central differencing schemes and implicit, but therefore unconditionally stable, Newmark-Beta schemes. It is shown to yield the same results as an existing algorithm for this purpose,...
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